>> WHAT WOULD HAPPEN IF EVERY HUMAN BEING ON EARTH DISAPPEARED? THIS ISN'T THE STORY OF HOW WE MIGHT VANISH. IT IS THE STORY OF WHAT HAPPENS TO THE WORLD WE LEAVE BEHIND. IN THIS EPISODE OF<i> LIFE AFTER PEOPLE...</i> "OUTBREAK." IT'S WHAT HAPPENS WHEN NATURE IS LEFT UNCHECKED. SOME ANIMALS ARE ATTACKED BY A DEADLY PANDEMIC. OTHERS BREAK OUT AND GO WILD. STEALTHY ENEMIES ARE ON THE MARCH, ATTACKING CITIES AROUND THE WORLD, LIKE THEY HAVE ALREADY HIT THIS CITY IN THE HEART OF AMERICA. WHEN NATURE ATTACKS, THE BIGGER THINGS ARE, THE HARDER THEY FALL. WELCOME TO EARTH... POPULATION: ZERO. ONE DAY AFTER PEOPLE. THOSE WHO KEPT THE FORCES OF NATURE UNDER CONTROL HAVE VANISHED. NATURE, LONG CONTAINED, IS POISED FOR AN OUTBREAK OF VIOLENCE AND CHAOS, DISEASE AND DISASTER. IN CHICAGO, THERE IS NO CREW TO MAINTAIN WRIGLEY FIELD, ITS ULTIMATE OPPONENT ALREADY EMBEDDED IN THE OUTFIELD WALL. NO ONE TO MAINTAIN THE SEARS TOWER OR JOHN HANCOCK CENTER, NOW STANDING LIKE GIANT TOMBSTONES. AND NO ONE TO MANAGE THE CHICAGO RIVER, ONE OF THE MOST HEAVILY ENGINEERED WATERWAYS IN THE WORLD. AS EACH DAY PASSES, NATURE BEGINS TAKING OVER. [THUNDER] 3 DAYS AFTER PEOPLE... A RAINSTORM HITS CHICAGO. IN THE TIME OF HUMANS, SUCH A DELUGE WOULD HAVE BEEN UNREMARKABLE. THE CHICAGO RIVER SHOULD FLOW INTO LAKE MICHIGAN, THE MASSIVE BODY OF WATER BORDERING THE CITY. BUT IN 1900, MAN TURNED ON NATURE. THE RIVER'S FLOW WAS REVERSED TO PREVENT POLLUTION OF CHICAGO'S DRINKING WATER. THIS LEFT MAN IN FIRM CONTROL OF WATER LEVELS, EMPLOYING ENGINEERING TECHNIQUES THAT WERE LATER USED IN BUILDING THE PANAMA CANAL. IN THE TIME OF HUMANS, WHENEVER IT RAINED, RIVER ENGINEERS MANAGED CANAL LOCKS AND SLUICE GATES TO DIVERT THE CURRENT AWAY FROM THE LAKE. BUT NOW, AFTER MORE THAN A CENTURY, THE RIVER GETS ITS REVENGE. >> IN A LIFE WITHOUT PEOPLE, WE WOULDN'T BE ABLE TO ANTICIPATE SUCH AN EVENT AND OPEN GATES TO MANIPULATE THE WATER LEVELS. THE ENTIRE RIVER SYSTEM WOULD FILL UP GRADUALLY JUST LIKE WATER IN A BATHTUB. INITIALLY, IT WOULD FLOOD LOW AREAS IN DOWNTOWN CHICAGO AND THE BASEMENTS OF BUILDINGS ALONG THE RIVER. >> SOON, THE HIGH RIVER LEVELS BEGIN SURGING SOUTH ALONG THE MANMADE CHANNELS TOWARDS THE GATES OF THE LOCKPORT CONTROLLING WORKS, 35 MILES DOWNSTREAM. THE 109-YEAR-OLD COMPLEX CONTROLS THE DRAINAGE OF THE CHICAGO RIVER. THAT'S ABOUT TO CHANGE. >> THE CASCADE OF WATER DROPPING ON THE DOWNSTREAM SIDE WOULD ERODE THE PIERS HOLDING THE GATES UP. >> THE DAYS WHEN MAN CONTROLLED THIS RIVER ARE OVER. >> THERE'S ABOUT 10 TO 20 BILLION GALLONS OF WATER BEHIND THESE GATES. WHEN THAT STRUCTURE COLLAPSES, THAT WALL OF WATER WOULD SEND A TORRENT DOWN THE DES PLAINES RIVER TO THE CITY OF JOLIET, WHERE IT WOULD OVERTOP THE RIVER WALLS AND FLOOD THE CENTER CITY. >> JUST DAYS AFTER PEOPLE, ENTIRE TOWNS IN THE AMERICAN MIDWEST ARE WIPED OUT BY RAGING WATER. ACROSS THE POND IN LONDON, TIME HAS RUN OUT FOR THE ICONIC BIG BEN. >> THE CLOCK BEHIND ME HAS BEEN WORKING CONTINUOUSLY FOR 150 YEARS NOW. AND THAT'S TAKEN IT THROUGH EXTREMES OF WEATHER, STORMS, THE LONDON BLITZ DURING THE SECOND WORLD WAR. >> BUT TO KEEP THE CLOCK RUNNING, IT HAD TO BE WOUND THREE TIMES A WEEK, A TASK THAT TOOK TWO ROYAL CLOCK MECHANICS SEVERAL HOURS TO COMPLETE WITH THE AID OF AN ELECTRIC MOTOR. >> IF THERE ARE NO PEOPLE AROUND, WITHIN A MATTER OF DAYS, THE CLOCK WILL STOP WORKING FOR THE FIRST TIME IN 150 YEARS, AND THE CHIMES WILL STOP CHIMING. >> THE CLOCK STOPS, BUT THE TOWER REMAINS, AT LEAST FOR NOW. DUE TO A CONSTRUCTION QUIRK, IT HAS ALWAYS LEANED 8.6 INCHES TO THE NORTHWEST, A LEAN THAT WILL ONLY GET WORSE OVER TIME. 2 WEEKS AFTER PEOPLE. OVER IN THE CULTURED SURROUNDINGS OF BUCKINGHAM PALACE, THE QUEEN'S LITTLE CORGIS DON'T NOTICE THAT THE CHIMES NO LONGER RING. IN THE TIME OF HUMANS, HER MAJESTY KEPT UP TO FIVE OF THE DWARFISH DOGS. SHE'D HAD CORGIS SINCE 1933. NOW THE QUEEN AND HER COURTIERS ARE GONE. THE CORGIS ARE ALL ALONE IN WHAT IS NOW JUST AN ORNATE 775-ROOM PRISON. THE PALACE'S 78 BATHROOMS PROVIDE A LIFESAVING WATER SOURCE. [CORGIS BARK] THOUGH THESE CANINES HAVE SHORT LEGS, THEY REACH THE TOILET WATER WITH THE AID OF THEIR LONG BODIES THAT ALLOW THEM TO STRETCH AND JUMP AS HIGH AS FOUR FEET. DESPERATE FOR FOOD, THE CORGIS FIND THEIR WAY TO THE ROYAL KITCHEN IN HER MAJESTY'S BASEMENT, A MAZE OF ROOMS WITH FOOD STOCKS THAT CAN LAST FOR A FEW MONTHS. AFTER THAT, THE FUTURE OF THE CORGIS WILL BECOME MUCH MORE UNCERTAIN. [ARF ARF] ONE MONTH INTO A LIFE AFTER PEOPLE. OUTSIDE ATLANTA, AN OUTBREAK OF KUDZU IS STARTING TO SPREAD FREAKISHLY. THE VINE WAS BROUGHT TO THE UNITED STATES IN 1876 FROM JAPAN FOR FARMERS TO FEED THEIR ANIMALS AND FOR EROSION CONTROL. IT WAS A MISTAKE. >> IT GROWS IN BRIGHT SUNLIGHT AND ON FERTILE SOILS VERY RAPIDLY. IT CAN GROW UP TO A FOOT A DAY, SO YOU CAN HAVE A 60-FOOT VINE WHERE YOU HAD NOTHING. >> KNOWN AS THE VINE THAT ATE THE SOUTH, KUDZU HAS A VAST ROOT NETWORK THAT SPREADS MORE THAN 15 FEET UNDERGROUND. IN THE TIME OF HUMANS, IT TOOK CONSTANT CUTTING BY A 25-MAN MAINTENANCE CREW, JUST TO KEEP THE ROADWAYS CLEAR IN ATLANTA AND THE SURROUNDING COUNTY. >> YOU HAVE TO KEEP GOING BACK AND KILLING THE ABOVEGROUND PORTION OF THE PLANT UNTIL YOU'VE EXHAUSTED THE ENERGY RESERVES IN THE ROOT SYSTEM. AND CONSIDERING THE SIZE AND THE DEPTH OF THOSE ROOTS, IT CAN BE A VERY DIFFICULT JOB. >> WITH NO NATURAL ENEMIES IN THE REGION AND NO HUMANS TO CONTAIN IT, KUDZU STARTS WREAKING HAVOC. THE NON-NATIVE SPECIES STARTS STRANGLING TREES, CLIMBING TELEPHONE POLES AND POWER LINES, COVERING BRIDGES AND ROADWAYS, AND ENVELOPING RURAL HOUSES. >> IT CREATES A SITUATION THAT THERE IS NOTHING GROWING THERE BUT THE KUDZU. AND WHAT YOU HAVE IS LITERALLY A DEAD SPOT IN THE ENVIRONMENT. >> AS KUDZU THRIVES, LIVESTOCK STRUGGLES. 60 MILLION HOGS ARE CONFINED ON NORTH AMERICAN FARMS. IN THE TIME OF HUMANS, THEY FED A DEMAND FOR 51 POUNDS OF PORK PER AMERICAN EVERY YEAR. NOW, THEY STARVE. PIGS IN CAPTIVITY HAVE BEEN KNOWN TO RESORT TO CANNIBALISM. 2 MONTHS AFTER PEOPLE, THE HOGS THAT SURVIVE BECOME FRANTIC. THE BIGGER 500-POUND BEASTS START PUSHING THEIR WAY OUT OF THEIR PENS. OTHERS BEGIN BURROWING UNDER SHEDS. EVENTUALLY, MILLIONS BREAK OUT INTO THE WILD. >> OF ALL THE DOMESTICATED LIVESTOCK THAT I WOULD PUT MY MONEY ON IN A WORLD WITHOUT PEOPLE, PROBABLY THE PIG GETS TOP PRIZE. PIGS ARE OMNIVORES. BASICALLY ANYTHING THAT YOU CAN EAT A PIG CAN EAT. THEY'RE ALSO VERY INTELLIGENT AND THEY'RE VERY GOOD DOERS, MEANING THEY CAN SURVIVE IN A VARIETY OF CONDITIONS. >> AFTER ESCAPING THEIR CONFINES, THE BARNYARD PIGS START BREEDING WITH THE 4 MILLION FERAL SWINE THAT LIVE PRIMARILY IN CALIFORNIA, TEXAS, AND FLORIDA. THE NEW PIG HYBRIDS BECOME LEANER, MEANER, AND MORE MOBILE, WITH LARGER TUSKS AND MORE HAIR. 3 MONTHS AFTER PEOPLE. IN LONDON'S BUCKINGHAM PALACE, THE QUEEN'S CORGIS HAVE DEPLETED THE STORES OF FOOD IN THE ROYAL PANTRY AND KITCHEN, WHICH ORIGINALLY STOCKED FOOD FOR BANQUETS OF UP TO 600 PEOPLE AND DAILY MEALS FOR A PALACE STAFF OF 400. THE CORGIS ONLY HOPE IS TO VENTURE OUT INTO THE CITY, AND FINDING A WAY OUT OF A BUILDING THAT HAS 775 ROOMS IS ONLY A MATTER OF TIME. HOW WILL THE CULTURED CORGIS SURVIVE? [BARKING] >> I THINK THE POPULAR IMAGE OF THE CORGI AS A PAMPERED PET INCAPABLE OF LIVING BY ITSELF DOESN'T DO IT A GOOD SERVICE. >> CORGIS WERE ORIGINALLY BRED TO BE WORKING DOGS ON WELSH FARMS, TO ROUND UP HERDS OF SHEEP AND CATTLE, A GENETIC TRAIT THAT WILL HELP THEM SURVIVE IN THE WILD. >> AS A WORKING DOG, THE CORGI IS ABLE TO MOVE VERY WELL OVER BROKEN COUNTRY. THEY'VE GOT SHARP TEETH. THEY'VE GOT AN EFFICIENT DIGESTIVE SYSTEM. SO THESE ARE ALL TRAITS THAT WOULD ALLOW THEM TO SURVIVE QUITE WELL EVEN IN THE ABSENCE OF HUMAN PROTECTION. >> STILL, CORGIS WOULD MAKE A TASTY SNACK FOR A BEAR OR WOLF. BUT THE QUEEN'S CORGIS WON'T HAVE TO WORRY ABOUT THAT. BOTH OF THOSE LARGE PREDATORS HAVE BEEN EXTINCT IN THE BRITISH ISLES FOR CENTURIES. THERE'S ANOTHER BENEFIT TO BEING A DOG ON THE LOOSE IN A POST-HUMAN BRITAIN. RABIES WAS ERADICATED HERE IN THE EARLY 20th CENTURY. IN AMERICA, IT'S A DIFFERENT STORY. PETS LUCKY ENOUGH TO ESCAPE THEIR HOMES NOW FACE ONE OF WILDLIFE'S MOST TERRIFYING SCOURGES. IN THE TIME OF HUMANS, MORE THAN 7,000 ANIMALS IN AMERICA, ABOUT 90 PERCENT OF THEM WILD, WERE ANNUALLY INFECTED WITH RABIES. [BARKING] THE VIRUS IGNITES THE NERVOUS SYSTEM AND INFLAMES THE BRAIN, CAUSING AN AGONIZING DEATH. IN POPULATION CENTERS ALONG THE EAST COAST AND IN TEXAS AND ARIZONA, ORAL BAIT VACCINES WERE DROPPED BY AIRCRAFT EACH YEAR, IN HOPES OF SUPPRESSING THE DISEASE IN SUCH FERAL ANIMALS AS FOXES, SKUNKS, COYOTES, AND RACCOONS. WITHOUT PEOPLE TO CARRY OUT THE INOCULATION PROGRAMS, AN OUTBREAK OF THE VIRUS SPIKES BY AS MUCH AS 30 PERCENT OVER THE NEXT SEVERAL YEARS. AMONG THE INFECTED, DOMESTIC CATS AND DOGS THAT VENTURE OUT AND ARE QUICKLY BITTEN BY THE WILD, RABID ANIMALS. >> THEY GO THROUGH A HYPER-AGGRESSIVE, HYPER-ACTIVE, ALMOST MADNESS. WE COULD CALL IT A FURY, WHERE YOU GET THAT CHARACTERISTIC FROTHING OF THE SALIVA AT THE MOUTH. SOME DOGS THAT ARE INFECTED WITH THE RABIES VIRUS HAVE BEEN KNOWN TO ACTUALLY BITE UP TO ANOTHER HUNDRED ANIMALS. >> ONE YEAR AFTER PEOPLE. PLANTS ARE ON THE RISE IN THE CITY OF CHICAGO. IN WRIGLEY FIELD, AMERICA'S SECOND OLDEST BALLPARK, THE ICONIC IVY IS CONTINUING TO EXTEND ITS GREEN TENDRILS. THESE VINES HAVE FLOURISHED HERE SINCE 1937 WHEN THEY WERE PLANTED TO DECORATE AND COVER THE OUTFIELD WALL. WITH NO GROUNDSKEEPERS AROUND TO GIVE THEM THEIR MONTHLY CLIPPING, THE IVY THREATENS TO OVERRUN THE WHOLE STADIUM. BUT THERE IS ONE THING HOLDING IT BACK. EACH VINE CAN ONLY GROW TO A MAXIMUM LENGTH OF 50 FEET IN THE CHICAGO CLIMATE. HOWEVER, AS THE VINES SHED THEIR LEAVES EACH WINTER, THAT ORGANIC MATERIAL STICKS INTO CRACKS IN THE BRICK AND CONCRETE. IT DECOMPOSES INTO SOIL, WHICH IN TURN PROVIDES A HIGHER PLATFORM FOR NEW VINES TO SPROUT. 5 YEARS AFTER PEOPLE, THE IVY HAS CRAWLED UP AND BLANKETED THE STANDS. IT ROOTS INTO THE AGING MORTAR, INSERTING MOISTURE INTO CRACKS AND BREAKING UP WALLS. BUT THE TRUE VICTOR IN NATURE'S RACE TO RECLAIM WRIGLEY FIELD ISN'T THE IVY. IN THE INFIELD ONCE PROWLED BY THE CHICAGO CUBS, BUCKTHORN, A THICK, DENSE SHRUB IS TAKING OVER. IT WAS BROUGHT FROM EUROPE IN THE MID-1800s AND IS ONE OF THE MIDWEST'S MOST THREATENING PLANT SPECIES. >> ONE OF THE WAYS THAT BUCKTHORN IS SPREAD IS THAT WHEN BIRDS EAT THE FRUIT OF BUCKTHORN, THE FRUIT ITSELF IS SORT OF HARSH ON THE INTESTINES OF THE ANIMAL. IT'LL ESSENTIALLY HAVE BIRD DIARRHEA. AND SO THE BIRDS AFTER CONSUMING A CROP OF BUCKTHORN FRUIT WILL FLY AWAY AND VERY QUICKLY DISSEMINATE THE PLANT. >> IN THE TIME OF HUMANS, GROUNDSKEEPERS AT WRIGLEY FIELD HAD TO REGULARLY MOW AND TREAT THE GRASS WITH CHEMICALS TO PREVENT ANY OF THE SEEDS FROM TAKING ROOT. BUT WITH NO MAINTENANCE CREWS AROUND, THE DROPPED SEEDS FROM THE BIRDS QUICKLY FERTILIZE ON THE INFIELD GRASS AND BEGIN SPROUTING A WILD, WOOLY HEDGEROW THAT GROWS TO 10 FEET TALL. >> YOU WON'T BE ABLE TO WALK THROUGH IT, NEVER MIND THROW A BALL IN THERE. >> 10 YEARS AFTER PEOPLE. IN DOWNTOWN CHICAGO, THE LANDMARK 110-STORY SEARS TOWER IS SLOWLY DETERIORATING. AFTER THE GREAT CHICAGO FIRE OF 1871, THE CITY BEGAN REBUILDING VERTICALLY, WITH NEW FRAMES OF STEEL. IT WAS THE BIRTH OF THE SKYSCRAPER. NOW, RAINWATER POOLS AND ROTS THE SEARS TOWER'S ROOF. MOISTURE SEEPS DOWN INTO THE STRUCTURE AND BEGINS RUSTING THE BOLTS HOLDING THE GIANT GLASS AND ALUMINUM PANELS ON THE EXTERIOR. FREEZING WIND, RAIN, AND SNOW OFF LAKE MICHIGAN VIOLENTLY BATTERS THE HULKING STRUCTURE. SOME OF THE PLATES PEEL OFF THE BUILDING AND CRASH INTO THE STREETS BELOW. FOR NOW, THE CITY OF CHICAGO IS STILL RECOGNIZABLE AS A ONCE-GREAT METROPOLIS. BUT WHAT WILL IT LOOK LIKE 30 YEARS AFTER PEOPLE DISAPPEAR? TO FIND OUT, WE DON'T NEED A CRYSTAL BALL. WE JUST NEED TO TRAVEL 30 MILES AWAY, TO ANOTHER LAKEFRONT CITY WHERE IT'S ALREADY HAPPENED. IT'S 30 YEARS INTO A LIFE AFTER PEOPLE. FOR A LOOK INTO THE FUTURE OF LAKEFRONT CITIES LIKE CHICAGO... ONE ONLY HAS TO VISIT GARY, INDIANA. THOUGH PARTS OF THE MIDWEST METROPOLIS ARE ALIVE AND WELL, HUGE SWATHS HAVE BEEN ABANDONED. GARY, INDIANA, ONCE HAD A THRIVING POPULATION OF NEARLY 200,000 PEOPLE. THEN A SLOW, UNFOLDING DISASTER HIT. >> GARY WAS FOUNDED IN 1906 BY U.S. STEEL, AND WAS CREATED AS A COMPANY TOWN FOR THE INDUSTRY. WHEN THE ECONOMY OF U.S. STEEL STARTED TO SLIDE DOWNWARD, THE ENTIRE CITY JUST STARTED TO VACATE AND BECOME ABANDONED. THE CITY THEN BECAME KIND OF KNOWN AS THE POMPEII OF THE MIDWEST, A CITY OF RUINS WHERE YOU COULD WALK DOWN THE STREET AND THERE WAS NO ONE HERE. IT'S JUST A CITY OF DECAY. >> LIKE CHICAGO, GARY GREW BECAUSE IT HELPED LINK THE GREAT LAKES TO THE TRANSCONTINENTAL RAILROAD SYSTEM. BUT NOW LAKE MICHIGAN IS THE SOURCE OF ITS DEMISE. >> THE WEATHER IN GARY IS EXTREMELY TOUGH BECAUSE WE'RE VERY CLOSE TO THE LAKE, WHICH BRINGS IN A LOT OF HUMIDITY IN THE SUMMER. AND IN THE WINTER, IT ALSO BRINGS IN A LOT OF FREEZING RAIN AND SNOW. WE HAVE A TREMENDOUS AMOUNT OF FREEZE/THAW CYCLES, AND IT'S NOT UNCOMMON TO GET 30 OR 40 FREEZE/THAW CYCLES A DAY IN THIS CITY, AND THAT LITERALLY JUST WREAKS HAVOC ON THE BUILDINGS. >> THE CONSTANT EXPANSION AND CONTRACTION OF MOISTURE IN THE CITY'S STRUCTURES DUE TO EXTREME TEMPERATURE FLUCTUATIONS-- AS MUCH AS 60 DEGREES IN A DAY, WITH FREEZING ICE THEN MELTING WATER-- CAN SPLIT WALLS LIKE A JACKHAMMER. GARY'S TRAIN STATION, BUILT IN 1910, WAS A CRITICAL MIDWESTERN HUB FOR TRANSPORTING STEEL FREIGHT AND THOUSANDS OF PASSENGERS. >> BOARDING IS COMPLETE. AMTRAK TRAIN NUMBER 69 TO THE ADIRONDACKS... HUNDREDS OF RAIL CARS MOVED THROUGH HERE EACH DAY. 30 YEARS OF UNTAMED NATURE HAVE TAKEN A FRIGHTENING TOLL. ONCE THE SKYLIGHTS SHATTERED, THE INTERIOR WAS OPEN TO A DELUGE OF WATER. MOISTURE RUSTED THE STRUCTURE'S STEEL SUPPORTS, WEAKENED THE MASONRY, AND CAUSED PARTS OF THE ROOF TO COLLAPSE. >> THIS BUILDING WOULD HAVE BEEN ABLE TO HAVE REMAINED IN GOOD USABLE CONDITION HAD SOMEONE SIMPLY PUT A NEW ROOF ON IT, JUST KIND OF MAINTAINED THE WINDOWS OR BOARDED IT UP. BUT WITHOUT THAT, THE BUILDING IS JUST BEING RAVAGED. >> ONCE A PLACE WHERE PEOPLE GATHERED FOR GRAND WEDDING CEREMONIES AND SOLEMN FUNERALS, ONLY A FEW BLOCKS AWAY FROM THE TRAIN STATION SITS GARY'S MOST NOTABLE CHURCH. >> THIS IS THE GARY METHODIST CHURCH THAT WAS CONSTRUCTED IN 1925 FOR THE GARY COMMUNITY. IT HAD A POPULATION OF ABOUT 3,000 PARISHIONERS. AFTER THE DECLINE OF GARY, IT DWINDLED TO LESS THAN 200, SO IT CEASED BEING A CHURCH IN 1975. >> ONCE PEOPLE FLED, THE ROUTINE MAINTENANCE LIKE PAINTING, CARPENTRY, AND PLASTERING ABRUPTLY HALTED. LIKE THE TRAIN STATION, WATER BEGAN COLLECTING ON THE ROOF, ROTTING A HOLE IN THE CEILING. >> THE HOLE IN THE ROOF GOT LARGER AND LARGER, ALLOWING MORE AND MORE WATER IN, MORE FREEZING, THAWING, CRACKING. IT HAS COMPLETELY DETERIORATED ALL OF THE ROOF BEAMS AND THE ROOF RAFTERS ABOVE US. ALL OF THE PLASTER HAS DETERIORATED, IS NOW ON THE FLOOR. >> WITHOUT THE PROTECTIVE COVERING OF PLASTER, THE EXPOSED BRICK ATTRACTS MOISTURE AND DEVELOPS MOSS. ONCE WEAKENED, IT BREAKS OFF AND BEGINS RAINING DOWN ON THE MAIN FLOOR OF THE SANCTUARY. >> WE'VE GOT A LOT OF MOLD GROWTH THAT'S EVIDENT ON THE BRICKS AND WE'RE STARTING TO SEE VERY SMALL PLANTS START TO GROW OUT OF THE BRICKS, SO IT'S NOT LONG BEFORE THOSE SMALLER PLANTS TURN INTO BIGGER PLANTS THAT TURN INTO TREES THAT ARE GOING TO DETERIORATE AND DAMAGE THE WALLS EVEN FURTHER. >> AFTER THREE DECADES OF BATTERING FROM HIGH WINDS, ROILING SUN, AND FREEZING SNOW, THE CHURCH IS CLOSE TO COMPLETE COLLAPSE. >> IT'S AMAZING THAT YOU CAN WALK INTO A SANCTUARY OF THIS SIZE AND ORIGINALLY IMAGINE THAT THERE WERE 3,000 PEOPLE THAT USED TO COME AND PRAY HERE AND WORSHIP HERE, AND NOW YOU COME IN AND THE CHOIR LOFTS ARE FALLING OFF THE WALLS. IF YOU WANTED TO IMAGINE WHAT IT WOULD BE LIKE WITH LIFE WITHOUT PEOPLE, YOU COULDN'T IMAGINE OR FIND A PLACE MORE EVOCATIVE THAN THIS. YOU JUST WONDER WHAT GOD HATH WROUGHT. >> AT THE CENTER OF DOWNTOWN, SITS THE 3,000-SEAT PALACE THEATER, ONE OF THE MOST LEGENDARY OLD SHOWPLACES IN THE MIDWEST. >> AT ITS TIME IN 1925, IT WAS JUST A WONDERFUL THEATER. OBVIOUSLY ALL OF THAT IS GONE NOW. IT'S NOT GONNA LAST MUCH LONGER. SMALL RODENTS AND ANIMALS AND DOG PACKS HAVE WALKED THROUGH THIS BUILDING AND CREATED TWO DISTINCT PATHS: FROM THE OUTSIDE IN AND INSIDE OUT. IT'S NOT UNLIKE WHEN YOU WALK INTO THE WOODS OR A LARGE PRAIRIE THAT YOU SEE PATHS THAT WERE CREATED BY ANIMALS. ALL THE YOUNG MEN IN GARY USED TO BE PROUD TO BRING THEIR DATES HERE BUT NOW, ONLY THE CHEAP SEATS REMAIN. >> THE RUINS OF GARY PROVIDE A GLIMPSE OF LIFE JUST 30 YEARS AFTER PEOPLE, A HARSH ORACLE FOR LARGE LAKEFRONT CITIES LIKE CLEVELAND AND DETROIT. IT'S 50 YEARS INTO A LIFE AFTER PEOPLE. THE DESCENDANTS OF THE ROYAL CORGIS STILL PROWL THE SUBURBS OF POST-HUMAN LONDON. BUT THEY AREN'T A BREED THE QUEEN WOULD RECOGNIZE. AFTER SEVERAL GENERATIONS OF INTERBREEDING WITH OTHER DOGS, ANY TRAITS INDICATING THEIR ROYAL LINEAGE ARE LONG GONE. [DOGS SNARLING] IN ONLY FIVE DECADES, PAMPERED PETS HAVE REVERTED TO WILD MUTTS. IN THE SOUTHERN UNITED STATES, KUDZU IS NOT ONLY SMOTHERING THE COUNTRYSIDE BUT INVADING ATLANTA AND ITS DOWNTOWN SKYSCRAPERS AND COMMERCIAL STRUCTURES. >> 50 YEARS AFTER PEOPLE ARE GONE, KUDZU COULD CERTAINLY COVER THE COCA-COLA BUILDING AND MOST OF THE MAJOR BUILDINGS IN DOWNTOWN ATLANTA, PROVIDED THAT THERE WAS A STARTING POINT FOR THEM ALREADY THERE. AND THERE IS KUDZU IN SMALL AND ABANDONED LOTS IN ATLANTA. KUDZU WOULD BEGIN TO CREEP OUT OF THOSE SITES. >> AFTER THE KUDZU VINES DIE IN THE WINTER, THE PLANT SENDS OUT NEW VINES IN THE SPRING THAT USE THE OLD, DEAD VINES AS A PLATFORM TO KEEP CLIMBING. THE DEEP UNDERGROUND ROOT NETWORK STORES VAST AMOUNTS OF NUTRIENTS WHICH PROVIDES THE PLANT WITH AN INEXHAUSTIBLE AMOUNT OF LATENT ENERGY. >> THERE COULD BE VINES A HUNDRED FEET UP THE BUILDING, UP ANY BUILDING. IT'S QUITE CAPABLE OF GROWING THAT FAST AND THAT FAR AND HOLDING ON TIGHTLY. THERE IS NO PHYSICAL BARRIER SHORT OF WATER OR A CREEK OR A RIVER THAT WOULD STOP THE GROWTH OF KUDZU. SO IT WOULD BE THE BEGINNING PHASES OF A GREEN BLANKET COVERING PARTS OF THE SOUTH. >> THE GEORGIA DOME, ATLANTA'S PREMIER SPORTS STADIUM, MUST FIGHT AN OPPONENT IT HAS NEVER KNOWN. >> THE WEIGHT OF THE VINES ALONE ON THE ROOF OF THE STRUCTURE WOULD PROBABLY CAUSE SOME COLLAPSE. THEY WOULD CAUSE THE WINDOWS TO BREAK. IT WOULD CERTAINLY TAKE OFF ANY AWNINGS OR SHADES OR ANYTHING THAT WAS ON THE SIDE OF THE BUILDING. >> THE OUTBREAK OF KUDZU SETS THE STAGE FOR AN EPIC DISASTER. EVEN IN THE TIME OF HUMANS, ATLANTA SUFFERED FROM PERIODIC DROUGHTS. NOW, HEAPS OF DRIED, BRITTLE KUDZU COVER THE CITY, CREATING A TINDERBOX. AS A THUNDERSTORM MOVES IN, LIGHTNING STRIKES. AND JUST LIKE IT DID DURING THE CIVIL WAR, ATLANTA IS BURNING AGAIN. THE SPREADING INFERNO LIGHTS UP THE SCULPTED FACES OF THE CONFEDERATE MEMORIAL ON NEARBY STONE MOUNTAIN. IN THE CITY OF CHICAGO, AFTER DECADES OF WILD GROWTH... WRIGLEY FIELD IS ALMOST UNRECOGNIZABLE. IN THE TIME OF HUMANS, THE GIANT 85-FOOT-HIGH WOODEN CENTERFIELD SCOREBOARD WAS ONE OF ONLY TWO IN A MAJOR LEAGUE STADIUM TO BE MANUALLY OPERATED AND WAS A CHARMING THROWBACK TO A SIMPLER TIME. BUT IT'S DEFENSELESS WITHOUT HUMANS TO MAINTAIN IT. IVY RAPPELS UP THE SCOREBOARD AS IT CRUMBLES UNDER A SIEGE OF TERMITES. TERMITES: ONE. CHICAGO CUBS: ZERO. DOWN BELOW, TANGLED THICK NETS OF SPONGY BUCKTHORN HAVE GROWN TO 20 FEET HIGH, SHUTTING OUT THE PLAYING FIELD. 100 YEARS INTO A LIFE AFTER PEOPLE. THE ELEVATED EL TRAIN IN DOWNTOWN CHICAGO HAS BEEN DISINTEGRATING FOR DECADES. IN 1892, THE FIRST SECTION OF THE ELEVATED RAILROAD, THE SECOND OLDEST IN AMERICA, BEGAN MOVING PASSENGERS AROUND BY LOCOMOTIVE ABOVE PARTS OF THE OLD STREETCAR LOOP THAT SURROUNDED DOWNTOWN CHICAGO. NOW, PAINT PEELS OFF THE STEEL GIRDERS HOLDING UP THE PLATFORM AND RUST BEGINS EATING AWAY AT THE EXPOSED IRON AND STEEL. BOLTS AND RIVETS ERODE AND CRACK, CAUSING A SHEER BREAK OF SOME OF THE SUPPORTING BEAMS. >> AS PIECES START TO FALL, YOU WOULD GET DISTORTION IN THE SUPPORTING MEMBERS AND THEY WOULD START TO TWIST AND FALL AND PULL DOWN OTHER NEARBY MEMBERS. SO YOU'D START TO HAVE A DOMINO EFFECT AS IT STARTS TO TWIST AND FALL, HITTING THE GROUND. >> IN LONDON, BIG BEN IS COVERED WITH VEGETATION, ITS WINDOWS BLOWN OUT, CHUNKS OF DECORATIVE STONEWORK CHIPPED AWAY. THE TOP OF THE ICONIC TOWER HAS ALWAYS LEANED 8.6 INCHES TO THE NORTHWEST. OVER DECADES, WITH NO HUMANS TO MANAGE THE WATER LEVEL IN THE THAMES, THE RIVER CONTINUALLY FLOODS THE SURROUNDING BANKS AND ROTS BIG BEN'S FOUNDATION. >> AFTER, SAY, A HUNDRED YEARS OR SO, THE TILT WITHIN THE TOWER WILL INCREASE AND GRADUALLY THE TOWER WILL BECOME MORE AND MORE UNSTABLE UNTIL FINALLY GRAVITY TAKES OVER AND THE TOWER ITSELF COLLAPSES INTO THE GROUND. >> IT'S 200 YEARS INTO A LIFE AFTER PEOPLE. IN DOWNTOWN CHICAGO, THE SEARS TOWER IS FINALLY BEGINNING TO TOTTER. DECADES OF FEROCIOUS WEATHER HAVE BATTERED THIS ICONIC LANDMARK INTO A HOLLOWED-OUT, HONEYCOMBED HUSK. THE SEARS TOWER HAS 104 SEPARATE ELEVATORS WITH MULTIPLE SHAFTS ENDING AT DIFFERENT LEVELS OF THE BUILDING. THE CABLES RUST AND SNAP, BUT THE ELEVATORS' BRAKES KICK IN. EVENTUALLY, THE BRAKES CORRODE AND THEY TOO GIVE WAY. >> YOU'LL HAVE THESE 104 ELEVATORS, AT DIFFERENT TIMES, OF COURSE, COME DOWN THOSE SHAFTS, BLASTING THROUGH THE FLOORS LIKE A BOMB, CUTTING THROUGH THE BUILDING AND, OF COURSE, FURTHER DRAGGING DOWN THE FLOORS AND THE STRUCTURE AROUND THEM. >> ONLY TWO ELEVATORS CONNECT THE GROUND FLOOR TO THE OBSERVATION DECK OVER A QUARTER MILE ABOVE THE STREET. ONE OF THE 3-TON ELEVATOR CABS FREEFALLS FROM THE TOP FLOOR, HITTING THE GROUND FLOOR AT MORE THAN 200 MILES PER HOUR, GENERATING MORE THAN 1.5 MILLION POUNDS OF FORCE ON IMPACT. BUT THAT WON'T BE ENOUGH TO TOPPLE THIS EPIC STRUCTURE. NATURE WILL NEED ONE FINAL SLEDGEHAMMER. 200 YEARS AFTER PEOPLE. THE SEARS TOWER MAKES ITS FINAL STAND. WHAT WILL BREAK THE BUILDING'S BACK ARE THE 114 PILINGS DRIVEN INTO THE BEDROCK THAT HOLD UP THE STRUCTURE. >> THE REAL ACHILLES HEEL IN THE SEARS TOWER IS YOU'VE GOT EIGHT FLOORS UNDERGROUND, AND ONCE YOU HAVE A LIFE WITHOUT PEOPLE, THOSE FLOORS ARE GONNA FILL WITH WATER. >> CHICAGO RIVER FLOODING WEAKENS THE LOWER INTERIOR COLUMNS SUPPORTING THE BUILDING, CAUSING IT TO COLLAPSE. >> IT COULD FINALLY REACH A POINT WHERE IT JUST SIMPLY FALLS ALL AT ONE TIME... ...INTO ONE JUST GIANT, HEAPING MASS OF TWISTED METAL AND CONCRETE AND GLASS. >> 250 YEARS AFTER PEOPLE. THOUGH THE SEARS TOWER COLLAPSED DECADES EARLIER, CHICAGO'S 100-STORY JOHN HANCOCK CENTER STILL STANDS. THE HANCOCK CENTER OWES ITS LONGEVITY TO THE UNIQUE CRISS-CROSS "X" BRACINGS OF STEEL BEAMS THAT LACE THE STRUCTURE OF THE BUILDING, GIVING IT EXTRA FORTIFICATION. BUT WITH ALL ITS WINDOWS BLOWN OUT AND CENTURIES OF MOISTURE CORRODING ITS STEEL FRAMING, SOMETHING'S GOT TO GIVE. AT THE CORNER OF THE 85th FLOOR, SEVERAL CRUCIAL BEAMS CONVERGE. ONE BY ONE, THEY RUST, BEND, AND FRACTURE FROM THE STREAM OF WATER DRIPPING DOWN FROM THE PERFORATED ROOF. AT A CRITICAL NOOK, A FINAL BEAM CRACKS AND SHEARS OFF. THE 15 FLOORS ABOVE IT START A CORNER-LINE CASCADE DOWN THE SIDE OF THE BUILDING THAT THEN SETS OFF A CATASTROPHIC FLOOR-BY-FLOOR IMPLOSION OF THE WHOLE EDIFICE. THREE CENTURIES AFTER PEOPLE, THE RABIES VIRUS STRUGGLES TO SURVIVE. THE DISEASE REQUIRES DENSE ANIMAL POPULATIONS IN ORDER TO SPREAD. AS DOMESTIC ANIMALS DIED OFF AND WILD ANIMALS DISPERSED FROM THE FRINGES OF THE HUMAN SETTLEMENTS WHERE THEY ONCE SCAVENGED, THE VIRUS COULD INFECT LITTLE MORE THAN SEVERAL THOUSAND ANIMALS PER YEAR. THE OUTBREAK IS OVER. 5,000 YEARS AFTER PEOPLE, ONLY EERIE REMINDERS OF OUR HISTORY REMAIN. STONE MOUNTAIN, JUST OUTSIDE ATLANTA, IS THE LARGEST PIECE OF EXPOSED GRANITE IN THE WORLD: 825 FEET HIGH AND MEASURING FIVE MILES IN CIRCUMFERENCE. IN THE 1920s, THE UNITED DAUGHTERS OF THE CONFEDERACY RAISED ENOUGH MONEY FOR WORK TO BEGIN ON A MASSIVE SCULPTURE OF SOUTHERN CIVIL WAR HEROES JEFFERSON DAVIS, ROBERT E. LEE, AND STONEWALL JACKSON ON THE NORTHERN SIDE OF THE ROCK. >> GRANITE IS, WITHOUT A DOUBT, ONE OF THE HARDEST, MOST COMPETENT ROCKS ON THE FACE OF THE EARTH. THERE IS HARDLY A CRACK IN THE ROCK. >> AFTER NEARLY 50 YEARS AND SEVERAL SCULPTORS, THE WORK WAS COMPLETED IN 1972. THE CARVED TABLET IS MORE THAN ONE FOOTBALL FIELD LONG AND IS AS TALL AS A 22-STORY SKYSCRAPER. AFTER FIVE MILLENNIA, 90 PERCENT OF THE CARVING REMAINS COMPLETELY INTACT. >> YOU JUST GET THE IMPRESSION THAT THIS THING WILL BE HERE FOREVER. >> BUT MOST OF WHAT MAN HAS BUILT WON'T BE. THE GREAT CITIES OF CHICAGO, ATLANTA, AND LONDON ALL AROSE BECAUSE OF THEIR GEOGRAPHICAL PROXIMITY TO THE LIFE-GIVING ATTRIBUTES OF NATURE: RIVERS, LAKES, FERTILE SOIL. NOW THE SILHOUETTES OF THESE ONCE-THRIVING METROPOLISES ARE VANQUISHED. THE RUBBLE LEFT BEHIND... CAMOUFLAGED BENEATH MOUNDS, COVERED IN DENSE VEGETATION, AND SWARMING WITH WILDLIFE. NATURE HAS BROKEN OUT AND CONQUERED. MAN'S CITIES HAVE LOST THE BATTLE IN A LIFE AFTER PEOPLE. IN THE NEXT EPISODE OF<i> LIFE AFTER PEOPLE...</i> HOW LONG WILL OUR HISTORY LAST? DESTRUCTION THREATENS THE CAPITALS OF MEN. SOME MONUMENTS STAND TALL, WHILE OTHERS CRUMBLE. LOS ANGELES SHAKES OFF ITS HUMAN PAST... AND IN THIS ABANDONED CAPITAL, THE JUNGLE HAS RULED
