THIS BRIDGE PROVED THE POWER OF A MIRACLE MATERIAL THIS AQUEDUCT LET CITIES BLOOM IN THE DESERT.

AND THIS CANAL OPENED UP THE WEST.

ALL OF THESE MADE THE LIST OF 10 MODERN MARVELS THAT CHANGED AMERICA.

I'M GEOFFREY BAER, AND I'LL BE YOUR GUIDE.

GEOFFREY: AS WE VISIT TEN AMAZING FEATS OF CIVIL ENGINEERING.

WE'LL DRIVE THE FIRST UNDERWATER TUNNEL BUILT FOR CARS AND RIDE THE RAILROAD THAT MADE COAST-TO-COAST TRAIN TRAVEL POSSIBLE.

THAT IS A MIND BOGGLING ENGINEERING ACHIEVEMENT.

WELL, IT WOULD BE LIKE YOU AND ME PLANNING TO GO TO THE MOON.

GEOFFREY: WE'LL SEE HOW ENGINEERS STOPPED ONE RIVER DEAD IN ITS TRACKS AND FORCED ANOTHER RIVER TO FLOW BACKWARD...

THIS WAS MEN, MACHINERY, AND PURE CHUTZPAH.

GEOFFREY: ...AND WE'LL LOOK AT A REMARKABLE NEW SYSTEM BUILT TO DEFEND NEW ORLEANS.

FIND OUT WHICH MODERN MARVELS MADE THE LIST OF 10 MODERN MARVELS THAT CHANGED AMERICA.

NOW LETS VISIT 10 MODERN MARVELS THAT CHANGED AMERICA.

IN CHRONOLOGICAL ORDER.

STARTING WITH AN AUDACIOUS ENGINEERING FEAT THAT OPENED UP THE WEST.

GEOFFREY: THOMAS JEFFERSON CALLED THE IDEA 'LITTLE SHORT OF MADNESS.'

MADNESS!

MADNESS.

GEOFFREY: A NEARLY 400 MILE LONG CANAL, TO BE BUILT WITH LITTLE MORE THAN HORSES AND SHEER MANPOWER, MUST'VE SEEMED COMPLETELY IMPOSSIBLE.

JUST, THE ODDS AGAINST THIS, AN INSURMOUNTABLE PROJECT.

THIS WAS THE ERIE CANAL.

GEOFFREY: THE DREAM OF A MANMADE WATERWAY LINKING THE ATLANTIC OCEAN TO THE FERTILE FARMLAND OF THE INTERIOR HAD LONG ELUDED AMERICANS.

GEORGE WASHINGTON HIMSELF HAD LOOKED FOR A WAY TO BUILD A CANAL THAT WOULD OPEN UP "THE WEST".

THE DREAM, THE VISION OF EVERYBODY IN EIGHTEENTH CENTURY AMERICA, IS THE GREAT WEST.

WHAT IS THE GREAT WEST?

IT'S NOT COLORADO, CALIFORNIA, IT'S THE OHIO RIVER VALLEY.

IT'S GETTING TO PITTSBURGH, THAT'S THE ORIGINAL GREAT WEST.

GEOFFREY: BIG OBSTACLES STOOD IN THE WAY.

THE BIGGEST: A FIFTEEN-HUNDRED-MILE WALL OF MOUNTAINS.

AT THE TIME, THE APPALACHIANS WERE REALLY THE GREAT BARRIER OF THE UNITED STATES AND WITH THIS BARRIER IN THE WAY THERE WAS NO WAY FOR THE COUNTRY TO GROW.

GEOFFREY: ANOTHER BARRIER, THERE WERE DISAGREEMENTS ABOUT WHETHER THE CONSTITUTION ALLOWED THE FEDERAL GOVERNMENT TO PAY FOR PUBLIC WORKS PROJECTS.

DC: OPERATIONAL COSTS ON A CANAL ARE PRETTY CHEAP BECAUSE YOU'RE JUST FLOATING, FLOATING IS CHEAP, BUT YOU'VE GOT TO BUILD IT, IT'S THAT CAPITAL COST OF BUILDING.

GEOFFREY: IF THERE WAS GOING TO BE A CANAL, IT WOULD HAVE TO BE BUILT BY A STATE.

NEW YORK CITY MAYOR DE WITT CLINTON TOOK UP THE CAUSE.

HE IS PASSIONATE ABOUT THE CANAL, RIGHT?

YEAH, HE LOVED THIS IDEA.

NEW YORK CITY, AT THE TIME, WAS IN COMPETITION WITH THE HARBORS OF PHILADELPHIA, THE PORT OF NEW ORLEANS.

THE IDEA WAS TO MAKE NEW YORK CITY THE CENTER OF THE WORLD.

GEOFFREY: AND CLINTON'S STATE HAD A PLACE WHERE THE ATLANTIC OCEAN COULD BE CONNECTED TO THE WEST FROM THE HUDSON RIVER TO LAKE ERIE.

DC: BETWEEN THE CATSKILLS AND THE ADIRONDACK'S THERE'S A GAP.

IT WAS ALMOST SORT OF BIBLICAL.

GOD MUST HAVE PLANNED FOR THIS, RIGHT?!

GEOFFREY: STILL, MERE MORTALS WOULD HAVE TO DIG CLINTON'S 363 MILE LONG CANAL AND THERE WERE NO PROFESSIONAL ENGINEERS TO HELP.

AT THE TIME, THE U.S.

DIDN'T HAVE AN ENGINEERING SCHOOL.

ASHLEY: THESE GUYS WERE AMATEURS.

THEY HAD SOME EXPERIENCE DOING LAND SURVEYING, BUT NOTHING ON THIS SCALE.

GEOFFREY: A STEAM-POWERED DIGGING DEVICE WOULDN'T COME AROUND FOR ANOTHER TWO DECADES.

SO MUCH OF THE WORK FELL TO NEW YORK FARMERS WITH SHOVELS.

THINK THOUSANDS OF MEN, PEOPLE WORKING WITH HAND TOOLS AND SHOVELS.

GEOFFREY: THEY WERE HELPED BY HARD-WORKING HERDS OF HORSES PULLING PRIMITIVE BULLDOZERS KNOWN AS "SLIP-SCRAPERS".

WHERE FORESTS STOOD IN THE WAY, INGENIOUS DEVICES CALLED "TREE FELLERS" LET A SINGLE MAN TOPPLE A TREE WITH A SIMPLE TURN OF A CRANK.

THEN STUMPS WERE YANKED OUT WITH OX-POWERED "STUMP PULLERS".

AND WHEN WORKERS HIT STONE, THEY HAD TO START BLASTING.

AND HOW DID THEY DO THAT?

THEY USED BLACK POWDER.

IT WOULDN'T HAVE BEEN DYNAMITE AT THIS TIME.

AND, IT WAS A PRETTY DANGEROUS JOB.

SET THE POWDER, AND THEN LIGHT EVERYTHING, AND RUN.

AND RUN!

[LAUGHS] GEOFFREY: BUT THERE WAS ONE MORE HURDLE TO CLEAR: BETWEEN THE HUDSON RIVER AND LAKE ERIE THERE WAS A 565 FOOT ELEVATION CHANGE.

SO CREWS BUILT A SYSTEM OF 83 "LOCKS".

SO NOW WE'RE GOING INTO A LOCK.

YES, ONE OF THE ENGINEERING MARVELS OF THE ERIE CANAL.

GEOFFREY: A LOCK WORKS LIKE AN ELEVATOR FOR A BOAT.

THE BOAT ENTERS A CHAMBER... OH LOOK, THE GATES ARE CLOSING.

GEOFFREY: ...AND THE CHAMBER IS FILLED OR DRAINED LIFTING OR LOWERING THE VESSEL.

WE'RE GOING TO GO DOWN 40 FEET.

DOWN WE GO!

GEOFFREY: THEN ANOTHER GATE OPENS, AND THE BOAT CRUISES ON.

HAVE A NICE DAY.

AFTER EIGHT YEARS OF DIGGING, THE CANAL OPENED ON OCTOBER 26, 1825.

ON THE INAUGURAL VOYAGE, NOW-GOVERNOR DEWITT CLINTON CARRIED 2 CASKS OF LAKE ERIE WATER AND POURED THEM INTO THE OCEAN.

A VERY SYMBOLIC WEDDING OF THE WATERS.

GEOFFREY: CANAL TRAFFIC WAS HEAVY FROM THE GET-GO.

SETTLERS MOVED WEST TO START NEW LIVES FARMING THE FRONTIER.

THEN SENT BARGES FULL OF WHEAT, BUTTER, AND LUMBER BACK EAST.

TOWNS SPROUTED ALONG THE CANAL TO PROCESS RAW GOODS.

EACH CITY SORT OF BECAME KNOWN FOR THINGS.

SYRACUSE BECAME KNOWN AS THE SALT CITY, ROCHESTER BECAME KNOWN AS THE FLOUR CITY.

GEOFFREY: THE ERIE CANAL WAS THE REALIZATION OF A LONG-HELD AMERICAN DREAM.

THE WEST WAS OPEN FOR BUSINESS AND THE YOUNG NATION HAD SHOWN IT HAD THE ENGINEERING MIGHT TO BUILD THE IMPOSSIBLE.

ASHLEY: THE ERIE CANAL IS SOMETIMES REFERRED TO AS AMERICA'S FIRST SCHOOL OF ENGINEERING BECAUSE THESE GUYS WERE LEARNING AS THEY WENT.

THE ERIE CANAL BECAME SORT OF THEIR LEARN AS YOU GO PROJECT.

GEOFFREY: TODAY, HE'S FAMOUS FOR HIS OTHER BRIDGE IN BROOKLYN, BUT JOHN ROEBLING FIRST REVEALED HIS BRIDGE-BUILDING SECRETS 16 YEARS EARLIER IN CINCINNATI.

WAS THIS KIND OF ROEBLING'S CALLING CARD TO GET THE BROOKLYN BRIDGE GIG?

THIS BRIDGE WAS THE LONGEST SUSPENSION BRIDGE WHEN IT WAS COMPLETED AND IT WOULD REMAIN THE LONGEST UNTIL THE BROOKLYN BRIDGE OPENED.

GEOFFREY: IT WAS BUILT DURING THE CIVIL WAR DESPITE THE FACT THAT IT CONNECTED A SLAVE STATE WITH A FREE STATE.

THE IDEA FOR THE BRIDGE CAME FROM A KENTUCKY COMPANY THAT HOPED TO TIE THE FORTUNES OF THE SLEEPY TOWN OF COVINGTON, KENTUCKY TO ITS BUSTLING NEIGHBOR ACROSS THE OHIO RIVER.

IT IMMEDIATELY SPARKED OUTRAGE.

THERE WERE MANY PEOPLE IN THE GENERAL ASSEMBLY OF OHIO THAT THOUGHT THAT SLAVERY WAS IMMENSELY WRONG.

AND SINCE THE COMPANY BUILDING THE BRIDGE WAS IN A SLAVE STATE, JUST OBTAINING A CHARTER FOR THIS BRIDGE WAS A DIFFICULT ENTERPRISE.

GEOFFREY: WHAT'S MORE, CINCINNATI COMPANIES WERE WORRIED ABOUT SENDING BUSINESS ACROSS THE RIVER AND SHIPPING INTERESTS WORRIED A BRIDGE WOULD BLOCK THE WAY.

STEAMBOAT OWNERS WERE AFRAID THAT THE STACKS OF THEIR STEAMBOATS WOULD NOT BE ABLE TO GET UNDER A BRIDGE.

GEOFFREY: THE STATE OF KENTUCKY GAVE THE BRIDGE-BUILDERS THE GREEN LIGHT UNDER THE CONDITION THAT THE COMPANY REIMBURSE SLAVEHOLDERS FOR SLAVES WHO ESCAPED ACROSS THE BRIDGE.

OHIO RELUCTANTLY OKAYED THE BRIDGE TOO, BUT INSISTED THE KENTUCKY COMPANY COULDN'T CONNECT WITH CINCINNATI'S STREETS.

AND THEIR BRIDGE HAD TO BE HIGH ENOUGH AND LONG ENOUGH TO STAY CLEAR OF STEAMBOATS.

THEY BRING ROEBLING INTO CINCINNATI BECAUSE THEY FIGURE HE IS THE ONE MAN WHO CAN MEET ALL OF THE STIPULATIONS.

GEOFFREY: JOHN ROEBLING WAS A GERMAN-BORN ENGINEER WHO HAD REVOLUTIONIZED BRIDGE-BUILDING WITH WIRE CABLES AND IRON ROPE.

LEGEND HAS IT HE WAS INSPIRED BY A CATASTROPHE CAUSED BY HEMP ROPE.

HE WITNESSED A TRAGIC ACCIDENT AND ONE OF THE WORKMEN HAD DIED AND HE SAID TO HIMSELF THAT I AM GOING TO DESIGN AND PATENT A KIND OF IRON ROPE THAT WILL HAVE SUCH A HIGH TENSILE STRENGTH THAT THESE KINDS OF ACCIDENTS WON'T EVER HAPPEN AGAIN.

GEOFFREY: NOW, ROEBLING WOULD HAVE TO USE HIS INVENTIONS TO STRETCH AN UNPRECEDENTED 1,057 FEET ACROSS THE RIVER.

BUT HE HAD A PLAN.

HE WOULD BUILD TWO MASSIVE TOWERS ON OPPOSITE BANKS AND SUSPEND ONE HUGE SPAN BETWEEN THEM.

SO AS LONG AS YOU CAN FOUND YOUR TOWERS ON EITHER SIDE OF THE RIVER YOU CAN STRING CABLES ACROSS AND HANG THE DECK OF THE BRIDGE.

GEOFFREY: THIS "SUSPENSION BRIDGE" WOULD BE STIFFENED WITH IRON TRUSSES AND DIAGONAL STAYS.

AND THOSE STAYS, I MEAN THEY'RE-- THIS BRILLIANT ENGINEERING SOLUTION, BUT THEY MAKE THE BRIDGE SO BEAUTIFUL, THEY'RE LIKE HARP STRINGS ALMOST, RIGHT?

IT'S NOT ONLY AN ENGINEERING ACCOMPLISHMENT, IT'S AESTHETICALLY VERY BEAUTIFUL.

GEOFFREY: ROEBLING BEGAN BUILDING THE BRIDGE IN 1856, BUT WORK QUICKLY GROUND TO A HALT.

THERE'S A NATIONAL ECONOMIC CRISIS, THEY RAN OUT OF FUNDS.

GEOFFREY: THE START OF THE CIVIL WAR FOUR YEARS LATER MADE ROEBLING'S BRIDGE BETWEEN NORTH AND SOUTH SEEM IMPOSSIBLE.

AS CONFEDERATE FORCES ADVANCED NORTH TOWARD CINCINNATI A LOCAL ARCHITECT BUILT A TEMPORARY FLOATING BRIDGE TO DEFEND THE CITY.

SEVENTY SOME THOUSAND SOLDIERS COULD COME OVER TO THE NORTHERN KENTUCKY SIDE TO BUILD FORTIFICATIONS, WHICH WERE ALL VERY SUCCESSFUL.

GEOFFREY: THE CONFEDERATE TROOPS RETREATED, BUT A PERMANENT BRIDGE NOW SEEMED LIKE A MATTER OF NATIONAL DEFENSE SO CONSTRUCTION RESUMED AND NOT LONG AFTER THE END OF THE CIVIL WAR, ROEBLING'S BRIDGE BETWEEN NORTH AND SOUTH WAS COMPLETED.

BUT JOHN ROEBLING KIND OF HAS ANOTHER JOB, RIGHT?

HE'S NOT HERE ANY MORE.

HE GOES TO BROOKLYN TO BEGIN TO DESIGN THE BROOKLYN BRIDGE.

GEOFFREY: THE BROOKLYN BRIDGE WOULD SOON SPAN AN EVEN GREATER DISTANCE, BUT ROEBLING'S CINCINNATI BRIDGE WAS THE PROOF OF CONCEPT THAT SUSPENSION BRIDGES WERE AN ECONOMICAL AND BEAUTIFUL WAY TO CONNECT THE NATION.

THE SUSPENSION BRIDGE, IT'S JUST POETIC.

IT'S ENGINEERING POETRY.

THE OAKLAND BAY BRIDGE, THE GOLDEN GATE BRIDGE, THE VERRAZANO BRIDGE, ALL THESE SUSPENSION BRIDGES ARE THE KINGS OF THE MEGA SPANS.

GEOFFREY: IT WAS AN ENGINEERING TRIUMPH THAT CREATED A TRULY UNITED STATES.

A RAILROAD THAT MADE IT POSSIBLE TO CROSS THE ENTIRE CONTINENT BY TRAIN.

THAT IS A MIND BOGGLING ENGINEERING ACHIEVEMENT, RIGHT?

YEAH, WELL, IT WOULD BE LIKE YOU AND ME PLANNING TO GO TO THE MOON!

GEOFFREY: IN THE RUNUP TO THE CIVIL WAR, MOST EVERYONE IN WASHINGTON, DC AGREED THAT AMERICA NEEDED A TRANSCONTINENTAL RAILROAD, BUT THE DEEPLY DIVIDED CONGRESS COULDN'T AGREE ON WHERE IT SHOULD GO.

THE SOUTHERN LEGISLATORS WOULD NOT LET A NORTHERN ROUTE GO IN BECAUSE IT WOULD GIVE THE NORTH SUPREMACY.

THE NORTHERN LEGISLATORS WOULD NOT ALLOW A SOUTHERN ROUTE BECAUSE IT COULD HELP EXPAND SLAVERY.

GEOFFREY: A CALIFORNIA ENGINEER NAMED THEODORE JUDAH PROPOSED A THIRD ROUTE.

MANY THOUGHT IT WAS PREPOSTEROUS.

PEOPLE CALLED HIM CRAZY JUDAH, RIGHT?

WELL, HE WAS OBSESSED.

HE PROBABLY WOULD HAVE BEEN A REALLY BAD DINNER GUEST BECAUSE INEVITABLY HE WOULD HAVE GOTTEN ONTO THE SUBJECT OF WANTING TO BUILD THE PACIFIC RAILROAD.

GEOFFREY: INSTEAD OF A ROUTE THROUGH THE NORTH OR SOUTH JUDAH PROPOSED A MIDDLE PATH TO SACRAMENTO.

STRAIGHT THROUGH THE SNOWY SIERRA NEVADA MOUNTAINS VIA THE INFAMOUS DONNER PASS.

IN THE WINTER OF 1846, 1847, 80 PEOPLE WERE TRAPPED AT THE EASTERN SHORE OF DONNER LAKE AND THERE WAS INDEED CANNIBALISM AND THERE WERE PEOPLE WHO ADMITTED TO PARTICIPATING IN CANNIBALISM.

GEOFFREY: BUT JUDAH'S TREACHEROUS ROUTE BECAME POSSIBLE OVERNIGHT WHEN SOUTHERN STATES SECEDED FROM THE UNION.

BECAUSE SUDDENLY THERE ARE NO SOUTHERN LEGISLATORS IN THE CONGRESS.

SO THERE'S NO PROBLEM AT SAYING: "WE'RE GOING TO BUILD A NORTHERN ROUTE.

NOW, LET'S JUST DECIDE WHICH ONE IT WAS."

GEOFFREY: JUDAH RUSHED TO WASHINGTON, WHERE HE MADE A CONVINCING CASE THAT HIS ROUTE WAS SHORTER AND THEREFORE CHEAPER.

PLUS, IT LED TO THE CAPITAL OF CALIFORNIA.

CALIFORNIA WAS THE NATIONS BANK AT THE TIME BECAUSE CALIFORNIA WAS STILL REAPING HUGE AMOUNTS OF GOLD OUT OF MINES.

GEOFFREY: ON JULY 1, 1862, THE PRESIDENT AUTHORIZED TWO COMPANIES TO START WORK.

PRESIDENT LINCOLN SIGNED THE PACIFIC RAILROAD ACT, WHICH AUTHORIZED THE UNION PACIFIC TO BUILD WESTWARD FROM COUNCIL BLUFFS, IOWA AND THE CENTRAL PACIFIC TO BUILD EASTWARD FROM SACRAMENTO, CALIFORNIA TO MEET AT A POINT TO BE DETERMINED.

GEOFFREY: AND EXISTING RAILROADS WOULD COMPLETE THE COAST-TO-COAST ROUTE TO THE EAST.

CRAZY JUDAH'S CENTRAL PACIFIC HAD TO MAKE IT THROUGH THE MOUNTAINS, BUT ALL OF THE EQUIPMENT THEY NEEDED WAS STUCK BACK ON THE EAST COAST AND, OF COURSE, THERE WASN'T A RAILROAD YET SO IT HAD TO GO THE LONG WAY.

PRIMARILY USED SAILING SHIPS THAT SAILED DOWN AROUND CAPE HORN ON THE SOUTHERN TIP OF SOUTH AMERICA AND THEN BACK UP THE PACIFIC COAST.

GEOFFREY: RECRUITING LABOR FOR THE BACKBREAKING WORK PROVED A CHALLENGE.

THE RAILROAD TURNED TO CHINESE LABORERS, MORE THAN 10,000 AT A TIME.

THE CONVENTIONAL WISDOM IS THAT CHINESE LABORERS WERE UNSKILLED, ILLITERATE, BUT ACTUALLY THEY WERE MINERS, THEY WERE STONE WORKERS, THEY WERE CARPENTERS.

GEOFFREY: TRAINS HAVE TROUBLE WITH STEEP HILLS.

SO IN SOME SPOTS WORKERS BUILT WOODEN TRESTLES TO CROSS DEEP RAVINES AND IN OTHER PLACES THEY CARVED SHELVES INTO MOUNTAINSIDES.

THE CHINESE WORKERS LITERALLY MOVED MOUNTAINS TO HELP BUILD THIS RAILROAD.

GEOFFREY: BUT IN SOME STRETCHES THE ONLY WAY TO GET A STEADY GRADE WAS TO TUNNEL THROUGH SOLID GRANITE WITH THE HELP OF HIGHLY-VOLATILE NITROGLYCERIN.

SUE: CHINESE DID KNOW ABOUT EXPLOSIVES.

AFTER ALL, WHERE DID FIRECRACKERS COME FROM?

GEOFFREY: PROGRESS WAS AS SLOW AS A FEW INCHES A DAY.

ON THE LONGEST TUNNEL, THEY EXPEDITED THE JOB BY BLASTING A VERTICAL SHAFT AND THEN EXCAVATING OUT FROM THE MIDDLE.

AND THESE CREWS WORKED TWENTY FOUR-SEVEN, AROUND THE CLOCK, TO BUILD THIS TUNNEL.

GEOFFREY: ONLY SIX YEARS AFTER CONSTRUCTION STARTED, THE EASTERN AND WESTERN RAIL LINES MET AT PROMONTORY SUMMIT, UTAH, ON MAY 10, 1869.

RAILROAD EXECUTIVES LELAND STANFORD AND THOMAS DURANT GOT TO DRIVE THE FINAL GOLDEN SPIKES.

LELAND STANFORD MISSED.

THE HAMMER WAS GIVEN TO THOMAS DURANT, HE ALSO MISSED AND A TELEGRAPHER WHO WAS ON SITE TAPPED OUT THE DONE SIGNAL.

AND SO THE NEWS WAS IMMEDIATELY TELEGRAPHED TO BOTH ENDS OF THE LINE.

IT WAS ONE OF THE FIRST NATIONWIDE INSTANT NEWS EVENTS.

[TRAIN HORN] GEOFFREY: WITH THE RAILROAD COMPLETE, THE TIME IT TOOK TO CROSS THE CONTINENT SHRANK FROM SIX MONTHS TO ONE WEEK.

THE TRANSCONTINENTAL RAILROAD STITCHED TOGETHER A COLLECTION OF FAR-FLUNG STATES INTO A SINGLE COUNTRY.

CALIFORNIA MIGHT AS WELL HAVE BEEN HAWAII, PRIOR TO THE COMING OF THE RAILROAD.

BUT THE RAILROAD GETS COMPLETED AND SUDDENLY EVERYBODY KNOWS EVERYBODY ALL OVER THE COUNTRY AND IT SPEAKS TO THE PASSION AND DRIVE THAT PEOPLE HAD TO SPAN ON THIS CONTINENT AND TO REALLY MAKE THIS A TRANSCONTINENTAL NATION.

GEOFFREY: IT WOULD PUT A REMARKABLE NEW MATERIAL TO THE TEST, DEFYING BOTH GRAVITY AND PUBLIC OPINION.

PEOPLE DOUBTED HOW SOLID THIS BRIDGE WAS GONNA BE?

THERE WERE DOUBTERS FROM THE VERY BEGINNING.

ONE OF THE COUNTRY'S MOST FAMOUS BRIDGE ENGINEERS SAID, "I WANT NOTHING TO DO WITH THIS."

GEOFFREY: IT DIDN'T HELP THAT ITS DESIGNER HAD NEVER BUILT A BRIDGE IN HIS LIFE.

THE THING YOU NEED TO KNOW ABOUT JAMES B. EADS IS THAT HE CAN DO ANYTHING HE SETS HIS MIND TO.

GEOFFREY: JAMES EADS WAS AN ENTREPRENEUR WHO RETIRED AT AGE 37 AFTER MAKING A FORTUNE SALVAGING SHIPWRECKS FROM THE MISSISSIPPI RIVER IN HIS HOMEMADE CONTRAPTION.

EADS BUYS A 40 GALLON WHISKEY BARREL, THERE'S AIR GETTING PUMPED DOWN INTO IT SO HE CAN KIND OF SIT IN THE BARREL WITH HIS FEET DANGLING DOWN.

AND YOU'RE JUST LIKE FEELING AROUND WITH YOUR FEET AND YOUR HANDS PULLING UP TREASURE.

GEOFFREY: THE MISSISSIPPI RIVER HAD BEEN BOTH A BLESSING AND A CURSE FOR EADS'S ADOPTED HOMETOWN.

ST. LOUIS WAS A PORT CITY THAT OWED ITS VERY EXISTENCE TO THE RIVER.

BUT IN THE AGE OF THE RAILROAD, THE MISSISSIPPI HAD BECOME A BARRIER.

WE HAVE TRAINS ON THIS SIDE OF THE MISSISSIPPI, WE HAVE TRAINS ON THAT SIDE OF THE MISSISSIPPI AND THERE IS NO WAY TO GET THE GOODS ACROSS EXCEPT BY FERRY.

GEOFFREY: CHICAGO, MEANWHILE, WAS SURPASSING ST. LOUIS AS THE ECONOMIC EPICENTER OF THE MIDWEST.

AND A CHICAGO RAILROAD TRIED TO BYPASS ST. LOUIS ALTOGETHER WITH A NEW BRIDGE UPSTREAM.

FIFTEEN DAYS AFTER IT'S OPENED, A BOAT HITS THAT BRIDGE.

A LOT OF PEOPLE ARE SUSPICIOUS BECAUSE THE BOAT THAT HITS THE BRIDGE IS FROM SAINT LOUIS.

SO SABOTAGE.

GEOFFREY: TO COMPETE, SAINT LOUIS NEEDED A RAILROAD ROUTE ACROSS THE RIVER AND JAMES EADS HAD AN UNCONVENTIONAL PLAN TO BUILD ONE.

HE KNEW HIS BRIDGE HAD TO BE SIXTEEN HUNDRED FEET LONG TO MAKE IT ACROSS THE RIVER.

AND OF COURSE HE HAD TO LEAVE PLENTY OF ROOM FOR BOATS.

BUT INSTEAD OF SUSPENDING HIS BRIDGE FROM ABOVE LIKE ROEBLING, EADS WOULD SUPPORT IT FROM BELOW, USING AN ANCIENT FORM.

EADS REACHES BACK IN HISTORY TO THE GREAT ROMAN BRIDGE BUILDERS, EADS BRINGS THAT ROMAN ARCH BACK TO LIFE.

GEOFFREY: MANY DOUBTED WHETHER THE AMATEUR BRIDGE-BUILDER'S ENORMOUS ARCHES WOULD HOLD UP.

BUT EADS HAD A SECRET WEAPON.

STEEL IS THE PERFECT MATERIAL FOR THIS BRIDGE BECAUSE IT IS STRONG AND RELATIVELY LIGHTWEIGHT.

GEOFFREY: STEEL HAD BEEN AROUND FOR THOUSANDS OF YEARS, BUT THANKS TO RECENT INNOVATIONS A STRONGER STEEL COULD NOW BE MASS-PRODUCED.

STEEL HAD ONLY BEEN USED FOR THINGS LIKE KNIVES, RIGHT?

STEEL WAS NEVER USED AS A LARGE SCALE BUILDING MATERIAL UNTIL EADS DECIDED THAT IT COULD BE DONE.

GEOFFREY: BUT EADS'S BIGGEST AND MOST DEADLY CHALLENGE WAS HIDDEN BELOW.

TO ENSURE THE BRIDGE WAS STABLE, ITS STONE PIERS HAD TO BE ANCHORED TO BEDROCK 100 FEET BELOW THE WATER'S SURFACE.

SO THIS IS WHERE HIS EXPERIENCE WITH THAT WHISKEY BARREL COMES IN, RIGHT?

THAT'S RIGHT.

GEOFFREY: TO DIG UNDERWATER, EADS DESIGNED A WATERPROOF CHAMBER WITH AN OPEN BOTTOM, CALLED A PNEUMATIC CAISSON.

WORKERS KNOWN AS "SUBMARINES" DESCENDED A STAIRCASE TO THE RIVER'S BOTTOM.

ASHLEY: HE PUMPS AIR INTO THE CAISSONS, THEY SETTLE ON THE SOFT SAND AT THE BOTTOM OF THE RIVER AND THEN, THEY START TO JUST SUCK THE SAND OUT.

THE MORE SAND THEY SUCK OUT, THE DEEPER THE CAISSON GOES.

GEOFFREY: BUT AS THE CAISSON SUNK DEEPER AND DEEPER, MORE AIR HAD TO BE PUMPED IN TO HOLD BACK THE WATER.

AND WHEN WORKERS RETURNED TO THE SURFACE, THE SUDDEN DEPRESSURIZATION CAUSED DEADLY GAS BUBBLES TO FORM IN THEIR BLOOD.

MORE THAN A DOZEN WOULD DIE OF "THE BENDS".

ASHLEY: ONE OF THE SYMPTOMS WAS A KIND OF PARALYSIS AND PEOPLE WOULD BE KIND OF HUNCHED OVER AND UNABLE TO STRAIGHTEN.

GEOFFREY: BUT THE SAFETY OF HIS WORKERS WASN'T EADS'S ONLY CONCERN.

THE PUBLIC STILL QUESTIONED WHETHER HIS STEEL BRIDGE WAS SAFE TO CROSS.

PEOPLE EXPECTED THAT IT SHOULD BE BULKIER IN ORDER TO SUPPORT THE AMOUNT OF WEIGHT THAT IT DID.

THEY WEREN'T USED TO THE AMAZING PROPERTIES OF WHAT STEEL COULD DO.

GEOFFREY: TO LAY THEIR FEARS TO REST, A CIRCUS OWNER LED AN ELEPHANT ACROSS THE FINISHED SPAN.

THE REAL FINAL TEST WAS JULY 2, 1874, THEY HAD FOURTEEN LOCOMOTIVES ON THE BRIDGE AT THE SAME TIME.

GEOFFREY: TWO DAYS LATER THE LONGEST ARCH BRIDGE IN THE WORLD WAS OPEN FOR BUSINESS.

THIS REMARKABLE SHOWPIECE FOR STEEL USHERED IN A NEW AGE FOR ENGINEERING, ARCHITECTURE, AND MANUFACTURING, A LEGACY AS ENDURING AS THE BRIDGE ITSELF.

WHEN EADS BUILT THIS BRIDGE HE SAID THAT THERE WAS NO NATURAL FORCE THAT COULD TAKE IT DOWN, IT WOULD STAND AS LONG AS THE PYRAMIDS.

IT COULD EASILY STAND ANOTHER TWO THOUSAND YEARS.

OUR NEXT MODERN MARVEL IS A RIVER THAT FLOWS...BACKWARDS.

GEOFFREY: CHICAGO MAY BE KNOWN FOR ITS SOARING SKYSCRAPERS, BUT THE CITY'S GREATEST ENGINEERING FEAT WAS SAVING ITSELF FROM ITS OWN SEWAGE.

THIS WAS MEN, MACHINERY, CREATIVITY AND PURE CHUTZPAH.

[LAUGHS] GEOFFREY: AS CHICAGO GREW FROM A TINY FRONTIER TOWN INTO A MAJOR METROPOLIS, ITS RIVER BECAME LITTLE MORE THAN AN OPEN SEWER.

THE CITY DUMPED ITS WASTE IN THE CHICAGO RIVER, WHICH FLOWED INTO LAKE MICHIGAN.

AND THAT'S WHERE THE CITIES DRINKING WATER COMES FROM, WHAT COULD POSSIBLY GO WRONG?

OH, PLENTY COULD GO WRONG.

THE ABSOLUTE DANGER TO ANY CITY WAS WATERBORNE DISEASE.

GEOFFREY: SO CHICAGO ENLISTED THE HELP OF ELLIS CHESBROUGH, AN ENGINEER WHO HAD BUILT BOSTON'S WATER SUPPLY SYSTEM.

ELLIS CHESBROUGH WAS THE KIND OF GUY WHO WOULD PROPOSE THINGS THAT PEOPLE, WHEN THEY'D HEAR IT, THEY'D GO, "YOU WANNA DO WHAT?"

GEOFFREY: HIS FIRST FEW SOLUTIONS FOR CHICAGO WERE AMBITIOUS, IF A LITTLE BIT SHORTSIGHTED.

FIRST, CHESBROUGH DESIGNED THE FIRST COMPREHENSIVE SEWER SYSTEM IN AMERICA.

TO MAKE SPACE FOR THE SEWERS, CHESBROUGH HAD THE CITY RAISED UP AS HIGH AS TEN FEET.

TIM: YOU HAVE A WHOLE ARMY OF PEOPLE WITH ONE JACK RIGHT NEXT TO THE OTHER.

AND THEN, AT THE COMMAND 'NOW' EVERYONE ALL AT ONCE PULLS JUST SO MUCH AND THE BUILDING SLOWLY RISES UP.

GEOFFREY: BUT THE SEWERS STILL EMPTIED INTO THE RIVER, WHICH FLOWED INTO THE WATER SUPPLY.

SO NEXT, CHESBROUGH BUILT A WATER INTAKE CRIB TWO MILES OUT IN LAKE MICHIGAN, WHERE THE WATER MIGHT BE CLEANER.

TWO TEAMS OF WORKERS DUG A TUNNEL 60 FEET BELOW THE BOTTOM OF THE LAKE.

TIM: IT WAS LIKE A PRECISION ARMY WORKING UNDER LAKE MICHIGAN IN THIS BRICK TUNNEL.

GEOFFREY: STILL, ALL IT TOOK WAS A HEAVY RAIN AND SEWAGE DRIFTED FROM THE RIVER OUT TO THE INTAKE CRIB.

SO EVERY NOW AND THEN THE SEWAGE WOULD MAKE IT OUT THERE AND-- MAKE OUT THERE AND THAT'S A PROBLEM.

GEOFFREY: BUT CHESBROUGH STILL HAD AN AUDACIOUS PLAN UP HIS SLEEVE: TO REVERSE THE FLOW OF THE CHICAGO RIVER!

YOU SEE, CHESBROUGH KNEW THAT IF YOU COULD DIG A DEEP CANAL WEST FROM THE CHICAGO RIVER THEN THE RIVER AND ALL OF THAT SEWAGE WOULD START FLOWING TOWARD THE MISSISSIPPI.

THE BASIC PRINCIPLE IS SIMPLY TO USE GRAVITY.

TO MAKE THE WATER FLOW AWAY FROM THE LAKE, YOU NEED TO MAKE THE CHANNEL LOWER THAN THE LAKE LEVEL, SO THAT WATER IS NATURALLY GOING TO FLOW TO ITS LOWEST POINT.

GEOFFREY: CHICAGO WOULD HAVE TO DIG A CHANNEL SIX TIMES DEEPER THAN THE ERIE CANAL AND FOUR TIMES AS WIDE.

AS WITH THE ERIE CANAL, THERE WERE PLENTY OF GUYS WITH SHOVELS, BUT NOW THERE WERE FANCY NEW MACHINES LIKE STEAM SHOVELS AND HYDRAULIC SUCTION DREDGES TO EXCAVATE THE EARTH AND MUCK.

PEOPLE CALLED THIS THE CHICAGO STYLE OF EARTH MOVING.

GEOFFREY: OF COURSE, THIS WHOLE PLAN TO SEND CHICAGO'S SEWAGE DOWN THE MISSISSIPPI DIDN'T SIT WELL WITH ITS OLD RIVAL DOWNSTREAM.

GEOFFREY: PEOPLE IN SAINT LOUIS, NOT SO HOT ON THIS IDEA?

WELL NO, SO THEY START LOOKING AT EVERY LEGAL REMEDY THAT THEY CAN.

GEOFFREY: AS ST. LOUIS GOT TO WORK ON A LAWSUIT TO HALT THE PROJECT, CHICAGO RACED TO FINISH THE FINAL SECTION OF CANAL.

IT'S JANUARY 2, 1900, IT IS COLD AND THEY START TO DIG.

THEY SEE SOME PEOPLE COMING OVER A HILL.

THEY THINK, OH MY GOSH, IT'S PEOPLE WITH AN INJUNCTION FROM SAINT LOUIS.

NO, IT'S A COUPLE OF NEWS REPORTERS.

WHEW.

GEOFFREY: BY DAWN THEY WERE FINALLY ABLE TO CUT THROUGH THE FROZEN CLAY HOLDING BACK THE WATER.

THE WATER STARTS TO SPILL IN.

YAY.

GEOFFREY: WITH CHICAGO'S WASTE FLOWING TOWARD ST. LOUIS, THE STATE OF MISSOURI FINALLY FILED SUIT.

THE CASE MADE IT TO THE U.S. SUPREME COURT, WHERE CHICAGO NOT ONLY PREVAILED, BUT IT GOT A PAT ON THE BACK.

OLIVER WENDELL HOLMES PUTS FORTH THE IDEA THAT THE WATER NOW IS CLEANER THAN BEFORE BECAUSE OF ALL THIS FRESH LAKE MICHIGAN WATER.

YES, OR AT LEAST THAT'S WHAT THEY SAID AT THE TIME.

GEOFFREY: WHILE THE REVERSED RIVER DID HELP SOLVE CHICAGO'S SEWAGE PROBLEM, THERE WERE SOME UNFORESEEN CONSEQUENCES.

THE CANAL HAS BECOME A HIGHWAY FOR INVASIVE SPECIES AND THE REVERSED RIVER SENDS 23 THOUSAND GALLONS OF PRECIOUS FRESH WATER TOWARD THE OCEAN EVERY SECOND.

SO SOME ARE NOW SAYING ITS TIME TO REVERSE COURSE, AGAIN.

BASICALLY CHANGE IT BACK AND LET THE WATER FLOW BACK TO LAKE MICHIGAN.

CHANGING IT BACK ISN'T THAT EASY, BUT THEY DID IT BEFORE.

GEOFFREY: IF ENGINEERS GOT IT WRONG, IT COULD PROVE DEADLY.

35,000 COMMUTERS WOULD DRIVE BELOW THE RIVER EVERY DAY IN THE FIRST UNDERWATER TUNNEL FOR CARS.

MOTOR VEHICLES GIVE OFF CARBON MONOXIDE, SO WITHOUT AN ADEQUATE VENTILATION SYSTEM YOUR TUNNEL WOULD BECOME A GIANT GAS CHAMBER.

GEOFFREY: UNDERWATER TRAVEL WAS NOTHING NEW, TRAINS HAD BEEN DOING IT FOR YEARS.

BUT AS A NEW FORM OF TRANSPORT TOOK OVER AMERICA'S STREETS, THERE WAS A DEMAND FOR AUTOMOBILES TO CROSS THE WATER.

AND ON NEW YORK'S HUDSON RIVER, A BRIDGE WASN'T GOING TO WORK.

BECAUSE THE WAR DEPARTMENT SAID, WE NEED A 130 FEET OF CLEARANCE SO THAT THE WARSHIPS CAN PASS UNDER THE BRIDGE GEOFFREY: A TUNNEL WOULD BE FAR CHEAPER, BUT MORE DANGEROUS.

IN PITTSBURGH, A TRAFFIC JAM IN A MOUNTAIN TUNNEL HAD POISONED MOTORISTS, SENDING 12 OF THEM TO THE HOSPITAL.

THE CHALLENGE WAS HOW DO YOU VENTILATE ALL THAT SPACE?

IT WAS SEEN AS A FRONTIER OF CIVIL ENGINEERING.

GEOFFREY: TWO ENGINEERS HOPED TO FIND A SOLUTION FOR A TUNNEL UNDER THE HUDSON RIVER.

THE FIRST, CLIFFORD HOLLAND, HAD EARNED A REPUTATION AS ONE OF THE NATION'S LEADING TUNNEL EXPERTS AFTER BUILDING SEVERAL SUBWAY TUBES.

IT WAS SAID THAT IF YOU SAT NEXT TO CLIFFORD HOLLAND AT A DINNER PARTY HE WOULD TALK ABOUT TUNNELS AS IF THEY WERE THE END ALL.

GEOFFREY: AND OLE SINGSTAD'S SPECIALTY WOULD BE VENTILATION.

THE ENGINEERS ORDERED A SERIES OF EXPERIMENTS TO BE CONDUCTED IN AN OLD COAL MINE.

WITH STUDENT VOLUNTEERS, AND THEY WOULD MONITOR THE AMOUNT OF CARBON MONOXIDE IN THE BLOOD STREAM.

SO THEY ARE DOWN THERE BREATHING CAR EXHAUST?

YEAH.

GEOFFREY: MANY ASSUMED THAT SINGSTAD WOULD SIMPLY VENTILATE THE TUNNEL FROM EITHER END.

THAT'S VERY UNWISE FOR SEVERAL REASONS, ONE OF WHICH IS, IF THERE'S A FIRE, THAT WOULD JUST FAN THE FLAMES.

GEOFFREY: INSTEAD, HE CAME UP WITH AN INGENIOUS PLAN TO BRING FRESH AIR FROM ABOVE.

HE WOULD BUILD FOUR VENTILATION TOWERS ON THE RIVERBANKS WITH 84 ENORMOUS FANS, WHICH WOULD SUCK FRESH AIR DOWN INTO THE TUNNEL.

YOU COULD CHANGE THE FRESH AIR EVERY NINETY SECONDS OR IN OTHER WORDS, FORTY TIMES AN HOUR.

WE ARE NOW ENTERING THE HOLLAND TUNNEL.

GEOFFREY: INSIDE THE TUNNEL FRESH AIR WOULD ENTER THROUGH CURBSIDE PORTS.

YOU CAN REALLY SEE THOSE VENTS.

GEOFFREY: AND DIRTY AIR WOULD BE DRAWN INTO DUCTS AT THE TOP OF THE TUNNEL, THEN OUT THROUGH THE TOWERS.

CLIFFORD HOLLAND, MEANWHILE, HAD TO CONTEND WITH CONSTRUCTING THE TUNNEL ITSELF.

HE WOULD BUILD TWO CAST IRON TUBES, EACH BIG ENOUGH TO CARRY TWO LANES OF TRAFFIC 93 FEET BELOW THE RIVERBED.

HOW IN THE WORLD DO YOU DO THAT?

ANGUS: THERE WERE FOUR CREWS.

TWO CREWS WERE GOING WESTBOUND TO NEW JERSEY AND TWO CREWS WERE GOING EASTBOUND FROM NEW YORK.

GEOFFREY: AND THEY ARE GOING TO MEET UNDERNEATH THE RIVER?

AND THEY HAVE TO BE PERFECTLY ALIGNED.

GEOFFREY: 400-TON SHIELDS CUT THROUGH THE ROCKY RIVER BOTTOM AT A RATE OF TWO-AND-A-HALF FEET PER DAY.

ANGUS: AND THEN, THERE ARE WORKERS AT THE FRONT END WITH PICK AND SHOVEL WHO ARE REMOVING THE MUD AND THE DIRT-- GEOFFREY: BY HAND?

BY HAND, PICK AND SHOVEL.

GEOFFREY: THEY WORKED IN A PRESSURIZED CHAMBER, MUCH LIKE AT THE EADS BRIDGE, AND THIRTEEN OF THEM WOULD DIE FROM THE BENDS.

CLIFFORD HOLLAND BRAVED THE SAME DANGERS AS HIS MEN, PERSONALLY OVERSEEING THE UNDERWATER WORK.

NEWSPAPERS CALLED HIM, THE HEAD MOLE.

CLIFFORD HOLLAND HAD NO LASERS, NO GLOBAL POSITIONING SYSTEMS, HE WAS USING STRICT ENGINEERING DISCIPLINES TO BRING HIMSELF INTO PERFECT ALIGNMENT.

GEOFFREY: AS THE TWO ENDS OF THE TUNNEL GREW CLOSER TO EACH OTHER, HOLLAND FELL ILL. DAN: HOLLAND SUFFERED WHAT SOME CALLED A NERVOUS BREAKDOWN AND A HEART ATTACK FOLLOWED.

GEOFFREY: TWO DAYS BEFORE THE ENDS OF THE TUNNEL MET PERFECTLY IN THE MIDDLE, CLIFFORD HOLLAND DIED.

GEOFFREY: THE HOLLAND TUNNEL WAS HAILED AS THE EIGHTH WONDER OF THE WORLD WHEN IT OPENED THREE YEARS LATER.

GEOFFREY: THERE WAS A FEAR THAT PEOPLE WOULD BE TOO SCARED TO GO DOWN IN HERE, BUT PEOPLE ACTUALLY LOVED COMING DOWN HERE, RIGHT?

YES.

NEW YORKERS WOULD OFTEN TAKE A SUNDAY AFTERNOON TO DRIVE OUT TO NEW JERSEY AND DRIVE BACK, JUST FOR THE THRILL OF GOING THROUGH THE TUNNEL.

GEOFFREY: TODAY 30 MILLION MAKE THE CROSSING EVERY YEAR THROUGH CLIFFORD HOLLAND'S TUNNEL.

DAN: HOLLAND SAW THAT TUNNELS ALLOWED CITIES TO START PUTTING MAJOR INFRASTRUCTURE, MAJOR TRANSPORTATION SYSTEMS BENEATH THE SURFACE.

AND THAT TUNNEL, THE HOLLAND TUNNEL IS THE STANDARD MODEL TODAY THAT WE SEE IN TUNNELS ALL OVER THE WORLD.

GEOFFREY: IT WAS DESIGNED TO DO THE IMPOSSIBLE.

IT STOPPED THE COLORADO RIVER DEAD IN ITS TRACKS.

THIS IS A BIG RIVER AND A POWERFUL RIVER, THE LEVEL OF HUBRIS OF HUMANKIND STANDING UP AND SAYING, "RIVER, SCHMIVER, WE'LL JUST STOP IT," AND THEY DID.

GEOFFREY: FOR THE THIRSTY PEOPLE OF THE BONE-DRY WESTERN STATES, NOTHING WAS MORE VALUABLE THAN THE COLORADO OR MORE DANGEROUS.

WHEN THE RIVER BUSTED THROUGH AN IRRIGATION CANAL IN 1905, IT CREATED AN ENTIRE INLAND SEA.

YOU'VE GOT SOME FARMERS IN SOUTHERN CALIFORNIA SAYING, "WHAT ARE WE GOING TO DO ABOUT THIS?"

GEOFFREY: A DAM ON THE ARIZONA-NEVADA BORDER WOULD NOT ONLY CREATE A CONSISTENT WATER SUPPLY, IT WOULD MAKE MONEY BY GENERATING POWER FOR AN UPSTART CITY TO THE WEST.

DC: SO THEN, ALL OF A SUDDEN LOS ANGELES BECOMES REALLY A KEY PART OF THIS BECAUSE THEY'RE THE ONES WHO ARE ACTUALLY GONNA PAY FOR THIS.

GEOFFREY: BUT DAMMING A RIVER POWERFUL ENOUGH TO CARVE THE GRAND CANYON WAS EASIER SAID THAN DONE.

IT WOULD TAKE A 70-STORY DAM, THE TALLEST IN THE WORLD, AND IT WOULD TAKE SIX CONSTRUCTION COMPANIES TO BUILD IT.

WHICH INCORPORATE THEMSELVES WITH THE HIGHLY CREATIVE NAME OF SIX COMPANIES.

[GEOFFREY LAUGHS] GEOFFREY: BY THE TIME CONSTRUCTION STARTED THE COUNTRY HAD DESCENDED INTO THE GREAT DEPRESSION.

SO THOUSANDS OF MEN DESPERATE FOR WORK FLOCKED TO THE JOB SITE.

THEIR BOSS WAS A TASKMASTER NAMED FRANK CROWE.

HE PUSHED WORKERS TWENTY-FOUR-SEVEN THROUGH 120-DEGREE HEAT.

THEIR NICKNAME FOR HIM IS 'HURRY UP CROWE,' THAT'S NOT A NICKNAME FOR SOMEBODY THEY LOVE.

GEOFFREY: THEIR FIRST JOB: MOVING THE RIVER!

WORKERS COULDN'T HAVE WATER RUSHING THROUGH THE JOB SITE SO THEY DIVERTED THE RIVER THROUGH TUNNELS ON EITHER SIDE OF THE CANYON.

THEY QUITE LITERALLY BORE HOLES IN THE CANYON, TWO HUGE ONES ON EACH SIDE, FIFTY FEET IN DIAMETER.

FIFTY FEET, THAT'S A FIVE STORY BUILDING!

GEOFFREY: INSIDE THE TUNNELS, THE DESERT HEAT MINGLED WITH EXHAUST FROM TRUCKS CREATING A LETHAL STEW.

AS MANY AS ONE WORKER DIED EVERY OTHER DAY DURING ONE AWFUL SUMMER.

THE DAM IS A TRIBUTE EITHER TO GREAT BUDGETING OR A HORRIBLE LACK OF INTEREST IN PEOPLE'S LIVES.

GEOFFREY: BY 1932, TWO TUNNELS WERE COMPLETE AND THE COLORADO RIVER CHANGED COURSE.

NOW, THEY HAD TO ENSURE THE CANYON WALLS WERE SOUND ENOUGH TO ANCHOR THE DAM.

[EXPLOSIONS] SO WORKERS SUSPENDED 800 FEET IN THE AIR CLEARED LOOSE ROCK.

THEY ARE COMING DOWN ON CABLES AND PLANTING DYNAMITE... [EXPLOSIONS] ...AND SWINGING BACK SO THAT THEY DON'T GET BLOWN UP.

THESE ARE THE ACROBATS.

THEY ACTUALLY HIRED SOME CIRCUS ACROBATS?

THEY DID.

GEOFFREY: IT WAS A DEADLY JOB.

AS WORKERS PLUNGED TO THEIR DEATHS, THEY COULD ONLY HOPE THEY FELL ON THE ARIZONA SIDE OF THE STATE LINE.

ARIZONA HAD DIFFERENT LAWS THAN NEVADA, WHEN IT CAME TO WORKMAN'S COMP.

I HEARD THAT IF A WORKER FELL THEY'D MOVE HIS BODY TO THE ARIZONA SIDE.

THEY MOVED SOME BODIES AROUND.

GEOFFREY: BY 1933, IT WAS TIME TO POUR THE CONCRETE, ENOUGH TO BUILD A SIDEWALK AROUND THE EARTH.

MICHAEL: IT'S A TWO YEAR PROCESS, JUST ABOUT.

TWENTY FOUR/SEVEN?

TWENTY FOUR/SEVEN.

GEOFFREY: FINALLY, THE DIVERSION TUNNELS WERE PLUGGED AND LAKE MEAD FILLED BEHIND THE DAM, SWELLING UNTIL IT WAS MORE THAN 500 FEET DEEP.

THE LAKE IS HELD BACK BY THE SHEER WEIGHT OF ALL OF THAT CONCRETE, WITH THE DAM'S GRACEFUL CURVE LENDING EXTRA SUPPORT.

IT JUST LOOKS LIKE THIS LITTLE TISSUE, THIS LITTLE THIN THING ACROSS THE CANYON.

MEANWHILE THE DAM, AT THE BOTTOM, IS 600 FEET THICK.

IT'S ALMOST AS THICK AS IT IS TALL.

GEOFFREY: BELOW THE DAM WATER FLOWS INTO A POWER PLANT WHERE IT SPINS 17 TURBINES GENERATING ELECTRICITY FOR CUSTOMERS IN THREE STATES.

ONE POINT THREE MILLION PEOPLE IN SOUTHERN CALIFORNIA GET THEIR POWER FROM IT.

GEOFFREY: AND LAKE MEAD SUPPLIES WATER TO AN ESTIMATED 25 MILLION PEOPLE.

THIS MADE IT POSSIBLE FOR LAS VEGAS TO BE THE LAS VEGAS WE KNOW.

GEOFFREY: THE HOOVER DAM TRANSFORMED THE REGION AND PROVED TO THE WORLD THAT WITH ENOUGH CONCRETE EVEN THE MIGHTIEST RIVER COULD BE TAMED.

THIS IS A PRECEDENT SETTING DAM.

ONCE THEY HAVE BUILT SOMETHING THIS BIG, THERE'S GONNA BE A LOT MORE DAM BUILDING, A LOT BIGGER DAMS.

IF WE CAN DO THIS, WE CAN DO ANYTHING.

GEOFFREY: IF YOU DRINK LOS ANGELES WATER, YOU SHOULD SAVOR EVERY DROP, BECAUSE IT TRAVELED 240 MILES ACROSS THE DESERT TO GET THERE.

SO WHEN YOU DRINK WATER IN LOS ANGELES-- YES?

THIS IS WHAT YOU'RE DRINKING?

THIS IS TWENTY FIVE PERCENT OF ALL THE WATER CONSUMED IN SOUTHERN CALIFORNIA.

GEOFFREY: LONG BEFORE L.A. WAS AMERICA'S SECOND BIGGEST CITY, IT WAS A SLEEPY FARM TOWN ON THE LOS ANGELES RIVER AND THAT RIVER QUENCHED THE CITY'S THIRST FOR MORE THAN A CENTURY UNTIL WILLIAM MULHOLLAND CAME ALONG.

A FORMER DITCH-DIGGER, MULHOLLAND TAUGHT HIMSELF ENGINEERING, AND ROSE THROUGH THE RANKS OF L.A.'S WATER DEPARTMENT UNTIL HE WAS ITS SUPERINTENDENT.

MULHOLLAND CAME TO REALIZE THAT LA WOULD INDEED CONTINUE TO GROW.

AND SO HE WAS WORRIED THAT HE WAS GOING TO RUN OUT OF WATER.

NATURALLY, THEN, HE FELT IT WAS HIS DUTY TO LOOK FOR WHERE IT WAS GOING TO COME FROM NEXT.

GEOFFREY: FIRST, MULHOLLAND BUILT AN AQUEDUCT FROM THE OWENS RIVER, 233 MILES AWAY.

THE PROJECT TURNED THE LUSH OWENS VALLEY INTO A BARREN DESERT.

TOWNS BEGAN TO SHUT DOWN, PEOPLE MOVED OUT, SOLD THEIR LAND.

GEOFFREY: BUT LOS ANGELES JUST KEPT GROWING AND SOON, MULHOLLAND WAS EYEING AN EVEN BIGGER PRIZE, THE COLORADO RIVER.

APRIL: EVERYBODY WAS AFTER THE COLORADO AT THAT POINT AND MULHOLLAND KNEW THAT IF YOU DIDN'T HURRY UP AND GET THE WATER AND START USING IT, YOU WOULD PROBABLY LOSE IT.

GEOFFREY: MULHOLLAND FOUND A WORKABLE ROUTE FOR AN AQUEDUCT, IT WOULD START 150 MILES DOWNSTREAM FROM THE HOOVER DAM.

BUT TO GET TO L.A., THE WATER WOULD HAVE TO MAKE IT OVER THE MOUNTAINS.

SO AN OLD-FASHIONED AQUEDUCT WASN'T GOING TO WORK.

TRADITIONALLY AN AQUEDUCT IS DESIGNED SO THAT THE WATER IS ALWAYS FLOWING DOWNHILL.

RIGHT.

YOU WANT TO USE GRAVITY AS MUCH AS POSSIBLE, OBVIOUSLY, IT'S WHAT THEY DID IN ROME.

GEOFFREY: BUT BEFORE CONSTRUCTION COULD START ON MULHOLLAND'S LATEST FEAT HIS CAREER WAS SUDDENLY RUINED.

SO IN THE LATE 1920S, THE SAINT FRANCIS DAM COLLAPSES.

AND IT'S A DAM HE DESIGNED AND BUILT AND CONSTRUCTED.

WHEN IT COLLAPSES IT JUST TAKES WITH IT WHOLE COMMUNITIES.

AND HIS CAREER IS EFFECTIVELY OVER.

GEOFFREY: OFFICIALS IN ARIZONA, MEANWHILE, WEREN'T TOO HAPPY WITH THE IDEA OF LOS ANGELES SIPHONING OFF THEIR WATER.

AND SOON AFTER CONSTRUCTION STARTED,\ ARIZONA'S GOVERNOR SENT IN THE TROOPS.

HE DECLARED MARTIAL LAW AND HE GOT HIS NATIONAL GUARD REGIMENT OUT TO THE RIVER BANK AND SAID, "LISTEN, YOU MUST PROTECT ARIZONA VIRGIN SOIL."

GEOFFREY: CONGRESS INTERVENED, AND WORK RESUMED.

AS AT THE HOOVER DAM, THEY FIRST HAD TO SLOW THE RIVER.

AND THE IDEA OF BUILDING THIS DAM IS TO CREATE THIS?

YES, LAKE HAVASU.

WHEN WE'RE GONNA LIFT WATER OUT, YOU DON'T WANT IT SWEEPING PAST LIKE A RIVER.

YOU WANT IT STANDING RELATIVELY STILL.

GEOFFREY: FROM HERE, THE WATER BEGINS ITS JOURNEY TO L.A., ACROSS THE DESERT, AND OVER FIVE MOUNTAIN PEAKS.

AT THE BASE OF EACH MOUNTAIN ARE NINE PUMPS, SOME WITH THE HORSEPOWER OF 80 CARS.

AND IT'S LITERALLY PUSHING THE WATER UP THE MOUNTAIN?

ABSOLUTELY.

AND EACH ONE OF THESE REPRESENTS ONE PUMP.

AND THEY LIFT WATER UP EACH OF THESE PIPES AND THEN SHOOT IT UP THAT MOUNTAIN.

GEOFFREY: AND THEN, THERE'S MOUNT SAN JACINTO, AT 11,000 FEET, IT WAS TOO TALL FOR THE PUMPS SO WORKERS SPENT SIX YEARS DIGGING A 13-MILE-LONG TUNNEL.

JEFFREY: AND IT'S SOLID GRANITE, SO IT WAS PROBABLY THE MOST DIFFICULT ENGINEERING FEAT OF THE ENTIRE AQUEDUCT.

GEOFFREY: THE AQUEDUCT ENDS AT THE EASTERN EDGE OF LOS ANGELES, WHERE THEY BUILT YET ANOTHER MANMADE LAKE!

IT SITS AT A HIGHER ELEVATION THAN L.A.

SO IT'S ALL DOWNHILL FROM HERE.

AND BY GRAVITY WE CAN DELIVER WATER TO LOS ANGELES, PASADENA, FROM THAT ONE SPOT.

GEOFFREY: THE FIRST DROPS OF WATER ARRIVED ON JUNE 17, 1941 IN PASADENA.

IT WAS ONE OF ONLY 13 CALIFORNIA TOWNS THAT TOOK THOSE FIRST SIPS BUT SOON, THE NEW WATER SUPPLY ALLOWED CITIES TO BLOOM IN THE DESERT.

WE NOW DELIVER WATER TO 19 MILLION PEOPLE, THAT'S ONE IN EVERY SIXTEEN AMERICANS.

GEOFFREY: BUT FOR THE ONCE-MIGHTY COLORADO RIVER, THIS HAS ALL COME AT A PRICE.

IT IS NINE PERCENT LOWER THAN IT USED TO BE JUST A FEW YEARS AGO.

THE COLORADO RIVER IS LIKE A PLUMBING SYSTEM, THE WAY WE HAVE TAPPED IT UP AND DOWN ITS STREAM AND DRAWN SO MUCH WATER OFF OF IT, THAT IT COULD GO COMPLETELY DRY.

GEOFFREY: INTERSTATE IT WAS THE LARGEST ENGINEERING PROJECT IN HUMAN HISTORY AND YOU MIGHT USE IT EVERY DAY.

REED: IT'S HUGE.

WE HAD NEVER UNDERTAKEN ANYTHING OF THAT SCALE BEFORE.

AND IT'S DONE [SNAPS] LIKE THAT.

GEOFFREY: PLANS FOR AN INTERSTATE HIGHWAY SYSTEM HAD BEEN AROUND SINCE THE GREAT DEPRESSION, FDR EVEN SKETCHED OUT POTENTIAL ROUTES.

DAN: FDR HANDED HIS BUREAU OF PUBLIC ROADS CHIEF, A MAP AND SAID, "I'VE GOT SIX LINES ACROSS THIS MAP, THREE GOING NORTH-SOUTH, THREE GOING EAST-WEST."

JUST SIX?

DAN: JUST SIX.

GEOFFREY: BUT IT WAS A SMALL-GOVERNMENT REPUBLICAN HELL-BENT ON COST-CUTTING WHO MADE THE 129 BILLION DOLLAR PROJECT A REALITY.

DWIGHT D. EISENHOWER HAD SEEN THE VALUE OF GOOD ROADS FIRSTHAND AS HE LED TROOPS THROUGH GERMANY DURING WORLD WAR TWO.

DAN: THEY'RE ALL ON THE AUTOBAHN, SUDDENLY, AND EISENHOWER WAS BLOWN AWAY BY THE MOVEMENT OF HIS OWN TROOPS AND HOW EFFECTIVE THAT WAS.

HE SAID, "WE NEED TO HAVE SOMETHING LIKE THIS."

GEOFFREY: WITH THE COLD WAR HEATING UP, IKE ARGUED THAT A HIGHWAY SYSTEM WAS CRITICAL TO NATIONAL DEFENSE.

YOU COULDN'T POSSIBLY GET OUT IN FRONT OF AN ATOMIC WEAPON, BUT EISENHOWER THOUGHT THAT REBUILDING THE CITIES, RESCUING PEOPLE, ALL OF THAT HARD WORK WOULD HAPPEN ALONG THE INTERSTATE SYSTEM.

GEOFFREY: BUT EISENHOWER ALSO MADE A PITCH TO CIVILIANS: THE INTERSTATE WOULD CUT GRIDLOCK, MAKE DRIVING SAFER, AND JUMPSTART THE ECONOMY.

DAN: EISENHOWER UNDERSTOOD TRUCKING AND HE KNEW THAT THE INTERSTATE SYSTEM WOULD CREATE CONNECTIVITY'S BETWEEN CITIES.

GEOFFREY: THE SENATE GAVE IKE'S IDEA THE GREEN LIGHT IN 1956 WITH A VOTE OF 89 TO 1.

DAN: THE NAME IS A NAME ONLY THE GOVERNMENT COULD GIVE IT.

IT'S THE DWIGHT D. EISENHOWER NATIONAL SYSTEM OF INTERSTATE AND DEFENSE HIGHWAYS.

GEOFFREY: THEY BROKE GROUND IN MISSOURI SEVEN WEEKS LATER AND JUST THREE MONTHS AFTER THAT, THE FIRST STRETCH OPENED IN KANSAS.

SO THEY'RE REALLY MOVING TO GET THIS BUILT.

DAN: IT WAS LIKE SPONTANEOUS COMBUSTION, SPONTANEOUS CONSTRUCTION.

GEOFFREY: FROM COAST-TO-COAST, CONSTRUCTION CREWS MADE WAY FOR 41,000 MILES OF NEW ROAD.

MOST EARLY INTERSTATES WERE PAVED WITH CONCRETE, ENOUGH OF IT TO BUILD MORE THAN 90 HOOVER DAMS AND IT WAS REINFORCED WITH MILLIONS OF MILES OF STEEL.

GEOFFREY: I GUESS IT MUST HAVE BEEN PRETTY GOOD FOR THE CONCRETE INDUSTRY AND THE STEEL INDUSTRY, HUH?

DAN: OH, IT WAS HUGE.

GEOFFREY: CREWS BUILT MORE THAN A HUNDRED TUNNELS, AND 55,000 BRIDGES, AND OVERPASSES.

THE STANDARD 16-FOOT CLEARANCE COULD ACCOMMODATE MILITARY CONVOYS.

THIS IS STILL THE STANDARD HEIGHT EVEN TODAY, RIGHT?

RIGHT.

IF THEY WANTED TO GET MINUTEMAN MISSILES, ICBMS, TO TRAVEL FROM SILO TO SILO, AND THEY NEEDED TO KNOW THAT THEY COULD DRIVE THEM ON THE INTERSTATE SYSTEM.

GEOFFREY: JUST AS EISENHOWER HAD PREDICTED, THE INTERSTATE WAS A BOON TO BUSINESS.

THE NEW NETWORK ALLOWED TRUCKS TO DELIVER GOODS DIRECTLY TO ANY DESTINATION, SOMETHING RAILROADS COULDN'T DO AND NEW ROADSIDE BUSINESSES WERE BORN.

GEOFFREY: SO NOW, EVERYWHERE YOU GO IN AMERICA, YOU GET OFF THE HIGHWAY, YOU SEE THE SAME THING.

DAN: EVERYONE WANTS A GOOD HAMBURGER, EVERYONE WANTS A GOOD CUP OF COFFEE, A CLEAN BED.

I THINK THE INTERSTATE SYSTEM KICKED INTO HIGH GEAR, THIS IDEA OF UNIFORMITY.

GEOFFREY: BUT THERE WAS ANOTHER SIDE TO THE INTERSTATE.

IT CUT DEEP SCARS THROUGH AMERICAN CITIES AS WIDE AS 26 LANES.

GEOFFREY: AND EISENHOWER ACTUALLY DIDN'T ENVISION OR EVEN WANT INTERSTATES GOING INTO CITIES, RIGHT?

RIGHT.

HERE'S THIS FISCAL CONSERVATIVE, HE KNEW THAT GOING TO THE CITIES WAS GOING TO BE EXPENSIVE.

GEOFFREY: BECAUSE YOU HAVE TO BUY UP NEIGHBORHOODS AND TEAR THEM DOWN, AND--?

DAN: EXACTLY.

GEOFFREY: AT THE SAME TIME, IT ACCELERATED AN EXODUS TO THE SUBURBS.

INFRASTRUCTURE HAD ONCE AGAIN PAVED THE WAY FOR NEW SETTLEMENT, MUCH AS CANALS AND RAILROADS DID IN THE CENTURIES BEFORE.

DO YOU THINK EISENHOWER, IN HIS WILDEST DREAMS, IMAGINED HOW THE INTERSTATE WOULD TRANSFORM AMERICA?

DAN: EISENHOWER KNEW THAT THIS WOULD BE TRANSFORMATIONAL.

BUT NOT EVEN EISENHOWER KNEW JUST THE IMPACT IT WAS GOING TO HAVE.

THE INTERSTATE SYSTEM WAS THE GAS ON THE FIRE THAT REALLY PUSHED US INTO THE MODERN AGE.

GEOFFREY: OUR LAST MODERN MARVEL MAY BE HUNDREDS OF MILES LONG AND THOUSANDS OF HORSEPOWER STRONG, BUT IT STILL MIGHT NOT BE ENOUGH TO SAVE NEW ORLEANS FROM THE NEXT BIG STORM.

YOU KNOW MOTHER NATURE IS ALWAYS GONNA GET THE LAST LAUGH, MOTHER NATURE IS MOTHER NATURE.

GEOFFREY: NEW ORLEANS HAS BEEN FIGHTING WATER FOR 300 YEARS AND MOST EVERYTHING IT'S DONE HAS ONLY MADE MATTERS WORSE.

THE CITY SAW ITS FIRST FLOOD IN 1719 JUST ONE YEAR AFTER IT WAS FOUNDED BY SIEUR DE BE EN VILLE.

RICHARD: HIGH WATER ON THE MISSISSIPPI RIVER, FLOODS BIENVILLE'S BRAND NEW PROJECT, HIS BABY.

GEOFFREY: SO THEY CONTAINED THE RIVER WITH EARTHEN WALLS KNOWN AS LEVEES, BUT THAT STOPPED THE RIVER FROM DEPOSITING THE SEDIMENT THAT HAD BUILT UP THE CITY'S HIGH GROUND IN THE FIRST PLACE.

EVERY FEW YEARS, HIGH WATER IN THE RIVER WOULD OVERTOP ITS BANKS, DEPOSIT SEDIMENT.

SO THEN, THE CITY-- THE CITY WAS BUILT ON THOSE HIGHER, WHAT WE CALL NATURAL LEVIES.

GEOFFREY: THEN, A SYSTEM OF PUMPS AND CANALS WAS BUILT TO DRAIN THE CITY'S SWAMPS AND KEEP THEM DRAINED DURING A STORM.

BY THE EARLY 1900S, THE SWAMP IS DRYING OUT, IT'S BECOMING DEVELOPABLE REAL ESTATE.

GEOFFREY: BUT AS WATER WAS SUCKED FROM THE SOIL, AIR POCKETS OPENED UP, AND THE CITY STARTED SINKING.

RICHARD: THE GOOD NEWS IS, THE METRO AREA IS STILL ROUGHLY FIFTY PERCENT ABOVE SEA LEVEL.

THE BAD NEWS IS WE USED TO BE A HUNDRED PERCENT.

GEOFFREY: THE UNINTENDED CONSEQUENCES OF THESE ENGINEERING EFFORTS WOULD PROVE TRAGIC IN 2005.

AS HURRICANE KATRINA SWEPT TOWARD NEW ORLEANS, A POWERFUL STORM SURGE INVADED THROUGH MANMADE NAVIGATION CHANNELS AND HIGH WATERS FLOWED INTO THE VERY CANALS THAT HAD BEEN BUILT TO DRAIN THE CITY.

THERE WERE NO CLOSABLE BARRIERS ON THE MOUTH OF THOSE OUTFALL CANALS.

THE SURROUNDINGS OF WHICH, BY THE WAY, HAVE DROPPED BELOW SEA LEVEL.

GEOFFREY: FLOODWALLS PROVED NO MATCH FOR THE RISING WATER.

RICHARD: THE WATER WAS CASCADING OVER AND IT DIDN'T HAVE ARMORING ON THE OTHER SIDE.

IT WEAKENED AND THE SHEER FORCE PUSHED IT OVER.

GEOFFREY: IN ALL, NEARLY 2,000 PEOPLE WOULD DIE IN THE STORM AND HUMANITARIAN CRISIS THAT FOLLOWED.

I THINK, KATRINA IS ONE OF THOSE CATASTROPHES THAT'S REALLY AFFECTED AMERICAN HISTORY.

THOSE IMAGES OF THOUSANDS OF MOSTLY POOR AFRICAN AMERICANS WHO WERE TRAPPED IN THE CITY, WERE APPALLING.

GEOFFREY: NOW, A DOZEN YEARS AND 15 BILLION DOLLARS LATER, THE ARMY CORP OF ENGINEERS HAS BUILT A RISK REDUCTION SYSTEM.

WE DO CALL IT A RISK REDUCTION SYSTEM FOR A GOOD REASON, WE CAN NEVER ELIMINATE RISK.

GEOFFREY: WHERE KATRINA'S STORM SURGE FORCED ITS WAY INTO THE CITY, THEY'VE BUILT A TWO-MILE LONG, 26 FOOT-HIGH BARRIER.

IT'S BEEN CALLED THE GREAT WALL.

WHAT WOULD HAPPEN IF A STORM SURGE CAME HERE NOW?

RENE: IT WOULD HIT THE WALL AND DISPERSE.

WHAT WE'RE DOING IS WE'RE TAKING THE FIGHT TO THE STORM RATHER THAN THE STORM COMING INTO THE CITY.

GEOFFREY: THE CANALS THAT ONCE LET WATER IN TO THE CITY CAN NOW BE CLOSED OFF WITH GATES AS BIG AS JUMBO JETS.

RENE: THEY LOOK LIKE LITTLE PIE WEDGES.

BIG PIE WEDGES.

OR BIG PIE WEDGES, YEAH.

GEOFFREY: AND THEN, PUMPING STATIONS CAN SUCK STORMWATER OUT OF THE CANALS AS FAST AS 19,000 CUBIC FEET PER SECOND.

RENE: THAT WOULD FILL AN OLYMPIC SIZED SWIMMING POOL IN ABOUT FOUR SECONDS.

GEOFFREY: AND WHERE THE OLD FLOODWALLS WERE EASILY UNDERMINED, NEW ONES HAVE PILINGS DRIVEN DEEP UNDERGROUND AND REINFORCED CONCRETE BASES.

SO IT'S AN UPSIDE DOWN T?

RIGHT, IT'S LIKE THAT.

THE WATER WILL OVERTOP, IT'LL HIT THAT CONCRETE, AND THEN DISPERSE.

GEOFFREY: BUT ONE OF LOUISIANA'S MOST EFFECTIVE BARRIERS AGAINST HURRICANES IS DISAPPEARING.

A CHUNK OF WETLANDS THE SIZE OF A FOOTBALL FIELD IS LOST EVERY 100 MINUTES, IN PART TO RISING SEA LEVELS AND INCREASINGLY-INTENSE STORMS.

RICHARD: COASTAL WETLANDS, SERVE THE FORM OF TERRESTRIAL FRICTION AGAINST STORM SURGES.

IT HITS THAT LAND.

IT'S LIKE A SPEED BUMP.

GEOFFREY: AND SO, NEW ORLEANS' BEST BET FOR SURVIVAL MIGHT LOOK LIKE THIS.

HERE WE GO.

RESTORING THE WETLANDS IS WHAT WILL TURN OUR CURRENT PROTECTION OF METRO NEW ORLEANS INTO SOMETHING A LITTLE BIT MORE LONG TERM AND SUSTAINABLE.

GEOFFREY: SEA LEVEL RISE AND EVER-MORE-VIOLENT STORMS POSE A THREAT NOT JUST TO NEW ORLEANS, BUT TO COASTAL CITIES AROUND THE WORLD.

AND YET, IT'S IMPORTANT TO REMEMBER THAT THESE KINDS OF CHALLENGES HAVE INSPIRED SOME OF THE MOST AMBITIOUS ENGINEERING SOLUTIONS IN THE PAST.

WHETHER DELIVERING WATER TO OUR FAUCETS, OR MAKING SURE IT'S CLEAN, CONNECTING OUR CITIES, OR LINKING AN ENTIRE NATION.

OVER THE PAST TWO CENTURIES CIVIL ENGINEERS HAVE WORKED BEHIND THE SCENES TO CONFRONT SOME OF OUR MOST PRESSING NEEDS AND WHEN THEY DO IT WELL IT'S EASY TO TAKE IT FOR GRANTED.

WHEN GRAND SCALE ENGINEERING IS A SUCCESS, WE DON'T THINK ABOUT.

NO ONE STOPS TO THINK ABOUT HOW THEY GET WATER OUT OF THE TAP.

PEOPLE DON'T THINK ABOUT WHAT IT TAKES TO LIFT AN AIRPLANE OFF THE GROUND.

WE JUST WATCH IT TAKE OFF AND LAND.

THESE ARE MODERN MIRACLES.

WE NEVER THOUGHT WE COULD BUILD A PYRAMID.

WE NEVER THOUGHT WE COULD BUILD A HUNDRED STORY HIGH-RISE.

WE NEVER THOUGHT WE COULD STOP THE COLORADO RIVER IN ITS TRACKS.

WE DIDN'T THINK WE COULD DO ALL OF THOSE, BUT WE DID AND THE FACT THAT WE WERE ABLE TO INSPIRES US TO TRY FOR THAT NEXT LEVEL OF ACHIEVEMENT.

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