Life After People_08of10_Armed & Defenseless
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00:00Imagine our planet without its people.
00:07Imagine that every single human being has simply disappeared.
00:12This isn't the story of how that might happen.
00:16It's the story of what happens to the world we leave behind.
00:23Now, in Life After People.
00:26Do strong defences mean ultimate survival?
00:30Or do the seemingly weak stand a better chance?
00:35Great warships come under renewed attacks.
00:38Farm animals fend for themselves.
00:42And a secret nuclear warhead takes aim at new targets on the ocean floor.
00:48Join us on a journey from the mile-high city
00:53to the bottom of the sea
00:56and to a desolate and deserted site in New York City.
01:01Welcome to Earth, Population Zero.
01:06Nothing on Earth was built tougher than the machinery of war.
01:24Fighter jets, battleships and fortified bunkers.
01:33But will these defences offer any protection in a life after people?
01:39Or will they be just as vulnerable as the most defenceless structures and creatures on Earth?
01:55One day after people.
02:00In the depths of the Pacific Ocean is a relic of the Cold War.
02:07A ticking time bomb.
02:13In 1968, the Soviet submarine K-129 sank under mysterious circumstances.
02:22It was carrying a mini arsenal of nuclear weapons,
02:25including two nuclear torpedoes and three SSN-5 Serb missiles,
02:30each with a one megaton warhead.
02:36In 1974, the CIA salvaged part of the submarine,
02:40but the rest of it, including the missiles, remains on the ocean floor.
02:46Almost three miles down.
02:52As well as each warhead's seven-pound plutonium trigger,
02:55the missiles are packed with lithium deuteride,
02:58a solid compound that supplies the hydrogen in a hydrogen bomb.
03:03The grey, salt-like substance will explode if it touches water.
03:11When the submarine sank, at least one of the warheads may have been damaged.
03:17One day after people, their tough metal skins are still keeping out the water, at least for now.
03:29Eighteen hundred miles to the southeast,
03:31the battleship Missouri sits quietly in Pearl Harbor on the Hawaiian island of Oahu.
03:39Permanently moored here as a museum ship since 1998,
03:43this was the last American battleship ever launched, and the last to be decommissioned.
03:48It's five feet longer and 18 feet wider than the Titanic.
03:56Launched in 1944, its decks witnessed the Japanese surrender in the Second World War.
04:06Its guns fired on their last targets in 1991 during Operation Desert Storm.
04:18The Missouri is well armed for fighting off enemy planes and ships.
04:23But down below deck, in the corner of the mess hall, is its key defense in a life after people.
04:36It's one of the control units for the Missouri's cathodic corrosion protection system.
04:43It prevents rust and corrosion by sending an electrical current to zinc rods attached to the steel of the hull.
04:50The electrically charged zinc draws corrosive reactions away from the steel,
04:55but this process is only effective when the metal is submerged.
04:59Above the waterline, cleaning and painting are the only defenses.
05:05Defenses that were breaking down even during the time of people.
05:10Let me show you some examples of some of the rust on board the USS Missouri.
05:14A lot of the surface rust will happen pretty rapidly once the paint system has failed.
05:18It'll break a lot of your brackets, your supporting members that hold your ladders, your piping systems.
05:24Eventually they're going to give way and they'll crash or they'll fall on their foundations.
05:39Two days after people.
05:44Some of the world's most defenseless creatures face a world for which they are completely unprepared.
05:52There are nine million dairy cows in the United States alone and they're used to being milked two or three times a day.
06:05But now the dairy is empty and the milking machines have been turned off.
06:15Milk cows are incredibly dependent upon humans.
06:18As soon as we disappeared and they were off their schedule, their regular milking schedule, they'd be confused.
06:25When is someone going to come and get me and bring me into the milking parlor?
06:29When is someone going to bring me more food?
06:33They'd be mooing, vocalizing, trying to let us know that they need some attention.
06:41While some will develop infections of the other, the pain and discomfort most suffer will only be temporary.
06:49Surprisingly, the vast majority of them would do what we call dry up.
06:53They would stop lactating.
06:55The milk that she retains in her udder would just absorb back into the body
07:00and her system would tell her, hey, time to stop producing milk.
07:05That would take about two weeks.
07:07But not all dairy cows are safe.
07:11Probably the animals that would be under the most stress and would have the biggest problem if humans disappeared
07:18would be the baby calves because they're incredibly vulnerable and dependent upon humans.
07:25Baby calves had to be hand-fed by humans twice a day
07:29because their mothers had been conditioned to mass-produce milk
07:32and paid little attention to their young.
07:38Now many adult cows are just as dependent on people for food.
07:43If the cattle could not get feed, they would wander around, they would look bewildered,
07:48they'd push against the gates.
07:50If they couldn't get the gates open, which they probably wouldn't be able to,
07:53they'd eventually become weaker, they'd lie down and eventually, without the feed, they would die.
08:08It's three days after people.
08:134,000 fighter jets, bombers and other aircraft lie in wait.
08:18Jets, bombers and other aircraft lie in formation in the Arizona desert.
08:27But this phantom fleet is covered in a ghostly white.
08:33And it's not pilots, but coyotes that prowl these grounds.
08:40This is the Aerospace Maintenance and Regeneration Center.
08:44In the time of humans, it was a graveyard and storage facility for mostly military aircraft.
08:53The planes here are better prepared for a life after people than anywhere else on Earth.
09:01The stark white latex coatings, known as spray-lat, is what keeps them in near-pristine condition.
09:09They're all around the cockpit, they're on the fuel cells.
09:12In the fuel tanks, the backbone up here, every screw has got a seal in it.
09:16Inside the internal fuel systems, those are seals in there.
09:21The seals keep out dust and rainwater, while the white color reflects heat.
09:26The interiors of protected aircraft never rise more than 10 degrees above the outside temperature,
09:31no matter how harsh the sun.
09:39For these aircraft, the end won't come from the sun, but from the ground below.
09:58Four days after people.
10:02Near Pearl Harbor, the hands on the clock of the iconic Aloha Tower have come to a stop.
10:15Installed in 1926, the famous clock is driven by heavy weights, which have now reached the bottom of their cycle.
10:23Ordinarily, they are reset by electricity every two days.
10:27But power is now permanently out on the entire island.
10:35This also means the defeat of the USS Missouri's electrically powered rust protection system.
10:45Seawater now begins to eat away at the tower.
10:52It eats away at its hull.
10:57And from the skies above, the Missouri comes under a new kind of aerial assault.
11:15Six months after people.
11:19The birds of Hawaii are flocking to their new favorite island.
11:26Birds certainly have no trouble getting to a place like that.
11:29They would treat it like any other small island.
11:33The birds bring new life to the decks of the Missouri,
11:36dropping undigested seeds that lodge into the ship's 53,000 square feet of wooden decks.
11:43The battleship Missouri, it has teak decks and so that's an organic start.
11:48You would get a buildup of soil and leaf litter just as you would any other place on land.
11:53It's all a matter of time.
11:57As the Missouri becomes the newest Hawaiian island,
12:01out in the Pacific, the metal casing on the Russian nuclear warhead is on its way to failure.
12:13It's 15 years into a life after people.
12:23In Pearl Harbor, the USS Missouri has reached the end of her rope.
12:29The ship is held to the pier with nylon mooring lines.
12:32If you notice, sir, this line here has a chink in it.
12:35After 15 to 20 years, the chink is gone.
12:38If you notice, sir, this line here has a chink in it.
12:41After 15 to 20 years, the mooring lines will part.
12:44The ship will break away from its mooring here in Pearl Harbor.
12:52As the lines snap, the mighty ship pulls away from the dock.
12:58Now adrift, what will be its fate?
13:0920 years after people.
13:15In the Arizona desert, the mummified aircraft waiting in an eternal holding pattern are showing signs of distress.
13:25Years of high winds have scattered these aircraft about like toys on a giant playground.
13:30In the time of humans, the planes had to be periodically realigned.
13:35Because these aircraft have a vertical stabilizer on it, the rudder,
13:39and makes the aircraft behave basically like a wind vane.
13:44We've had microbursts in the neighborhood of 120 miles an hour,
13:48which is enough to make most of these aircraft move around a little bit.
13:53The protective coatings on any planes that might be pulled back into service again also had to be maintained.
14:00Those that didn't receive this care suffered the consequences.
14:07This spray lat, as we see it right now, is really not serving its function anymore.
14:12Rainwater can get in under here, and it can actually seep out of here.
14:17Now, after two decades without maintenance, every plane is taking a beating.
14:22The paint is wearing thin, and rust is corroding the joints.
14:26The canopies are clouding from UV damage, and fighter jet engines have become homes for birds.
14:36The aircraft is now in a state of emergency.
14:41Wings on these aircraft are not likely to fall off.
14:44The wing structure is the strongest structure in the aircraft.
14:47It supports the aircraft when it's in flight, and when it's on the ground, taking all the ground loads.
14:51So, in a life after people, you're likely to see the wings still attached to these aircraft long into the future.
14:59But these planes won't stay here long enough to lose their wings.
15:03What we're seeing here is an example of some of the erosion caused by rainwater runoff.
15:07This is something that's common to all the aircraft that are stored here.
15:11And the chances are very good that this sort of erosion could have occurred in a single storm.
15:19As the desert rains sculpt out soil from below, desert winds sweep in directly.
15:25This is a very dangerous situation.
15:28As the desert rains sculpt out soil from below, desert winds sweep in dust from above.
15:34The earth begins to swallow what was once a mighty fleet.
15:47It's 25 years into a life after people.
15:53Three Russian nuclear missiles still sit on the bottom of the Pacific.
15:59Each one megaton warhead contains a substance that explodes on contact with water.
16:04The substance is sealed inside a tough metal casing coated with a heat or high-stress atmospheric re-entry shield.
16:16But with the pressure of the deep ocean, even a small crack in one of the casings can be fatal.
16:2225 years after people, the sea begins to leak into one of the bombs.
16:33The explosion is muted by the same ocean pressure that opened the crack,
16:37pressure the equivalent of being crushed by a 1.75 million pound weight.
16:46The bomb's plutonium would be scattered over a small area,
16:49and any sea creatures that came into contact with it would die of radiation poisoning.
17:0530 years after people.
17:09On land, most of the world's dairy cows have died out.
17:13Even those that found enough food on the farm or were able to escape their pens couldn't find a way to reproduce.
17:22In order to keep producing milk, dairy cows needed to be pregnant at least once a year.
17:30In the time of humans, this was frequently achieved through artificial insemination.
17:34Many dairy cows spent their whole lives without ever laying eyes on a bull.
17:40There were exceptions, and now these small pockets of surviving cows
17:44will begin a rapid evolutionary change that will take them back to the wild.
17:52Places like the plains of Colorado will make perfect grazing ground.
18:02In Colorado's capital, the state of Colorado,
18:06in Colorado's capital city of Denver,
18:09the most distinctive building in the skyline is the 50-story Wells Fargo Center.
18:17Built in 1983, it was nicknamed the Cash Register Building
18:21after the unique curved shape of its glass-covered roof.
18:28The distinctive design of the structure actually posed a surprising problem.
18:33In the snowy climate of the mile-high city, engineers had to install heating coils in the roof
18:38to prevent snow from piling up and then sliding down the side of the building.
18:49With the coils no longer functioning, the building now wears a crown of icy snow
18:53that drips moisture into the floors below.
18:56Every now and then, the center of Denver is witness to an urban avalanche.
19:03THE AVALANCHE
19:16Forty-five years after people.
19:20Man's footprint on Earth is getting smaller by the day.
19:24It's a future that's already here,
19:26less than a mile off the coast of one of the biggest cities in the world.
19:32While Manhattan Island has a population of one and a half million people,
19:38nearby, North Brother Island has a population of zero.
19:46The first buildings were constructed here in the 1880s.
19:52The city-owned island served many purposes over the years,
19:57housing returning Second World War veterans,
20:02quarantining victims of infectious diseases,
20:07and later, treating drug addicts.
20:13These former residents have all left an unusual mark on the island's life after people.
20:20Behind me is a building that was built as an infectious disease hospital in 1943.
20:28It was actually used until 1964.
20:31By that point, the place where I'm standing
20:34was actually a broad, well-maintained boulevard that cut through the island.
20:38It was the island's main street.
20:41This hydrant is right in front of the hospital,
20:44and it actually stood right on the curve at the edge of the street.
20:48Underneath the plant life is where the pavement was.
20:51There's about an inch of soil here now.
20:53It took about 45 years to accumulate.
20:57Riverside Hospital on North Brother Island was commissioned in 1881.
21:05Demolished in the mid-20th century,
21:07a handful of its original buildings still remain.
21:12It was here, in 1907,
21:14that New York quarantined its most notorious carrier of an infectious disease,
21:22Typhoid Mary.
21:27Typhoid fever is a deadly disease usually carried by unclean water.
21:32Massive outbreaks were becoming uncommon as sanitation improved,
21:35but Typhoid Mary was a special threat to New York.
21:41Mary Mallon was a cook, a so-called healthy carrier,
21:44who spread the disease but never became ill herself.
21:50She was officially blamed for infecting 53 people,
21:53though many believed her responsible for up to 1,400 cases in all.
22:00She was confined to North Brother Island on two different occasions,
22:03the first in 1907.
22:06She eventually died on the island in 1938.
22:15Isolated from the city by water,
22:17North Brother Island was entirely dependent on boats
22:20to keep its population supplied with everything from food to fuel.
22:29This coal dock served North Brother Island until around 1960.
22:34The dock actually was the unloading point for barges that would bring coal here.
22:43Most of the planks are now missing,
22:45but there are giant iron bolts that are 10, 12 inches deep
22:49and it gives you some idea of how deep the timbers were.
22:53We're actually standing on a concrete platform
22:57that is suspended over the waterway and over the beach
23:00with wooden piers, wooden pilings.
23:05The concrete has actually sunk and cracked
23:08because the pilings have started to deteriorate.
23:12Life was seldom easy in this place,
23:15where critically ill people hoped for cures
23:18from diseases that terrified the outside world.
23:24The structures that sheltered them are now in critical condition themselves.
23:31In the oldest of the brick buildings,
23:33decades of freeze-thaw cycles are prying walls open.
23:38Inside, the old coal boilers are rusting away from moisture,
23:44while the rest of the hospital succumbs
23:46to the unchecked growth of insidious plant life.
23:50We're here at the entrance to the hospital.
23:53This served as a drug rehab centre.
23:56Patients had to be brought here. This is an island.
23:59Many of the plants that are growing here also had to be brought here.
24:04Invasive vines like kudzu, honeysuckle and Asiatic bittersweet
24:08have taken over the island
24:10and, in doing so, have given water birds a new home.
24:15The island represents critical nesting habitat.
24:20The water birds have been here for a long time.
24:23They've been here for many, many years.
24:27These types of birds don't just nest anywhere.
24:30They need a certain amount of protection, distance from predators.
24:35So North Brother Island is one of the few patches in New York State
24:39where these birds are able to nest.
24:46After diseases like TB and typhoid were well contained,
24:49the hospital became a sanitarium for people
24:52who needed a respite from their difficult lives.
24:57Before it was abandoned,
24:59open lawns and well-tended grounds surrounded the buildings.
25:05In 45 years of neglect,
25:07the entire hospital appears to have gone into hiding.
25:11Believe it or not, these were the tennis courts in North Brother Island,
25:15Riverside Hospital.
25:17We're seeing 40 years' worth of plant succession,
25:20naturalising the site, soil accumulation.
25:23You can just kick away some of the organic matter.
25:28We've got the asphalt, former surface.
25:33A layer of soil now covers the old tennis court
25:36where battle-hardened veterans once tried to forget the horrors of war.
25:41Now, nature has attacked the asphalt with its own weapons.
25:47This is a Norway maple.
25:49It's growing around the post that held the tennis net.
25:53The seed probably dropped in a crack around 1964.
25:56It's growing for about 44 years.
25:59Could you imagine playing in a tennis court like this now?
26:05The island's web of vine has found its way inside the buildings as well.
26:12We're in one of Riverside Hospital's large general wards,
26:16originally built to house tuberculosis patients.
26:19It was never used for that purpose.
26:21The only thing alive here now is the porcelainberry.
26:26This has grown up from the ground,
26:28up to this fourth floor, through this fourth floor window.
26:32Porcelainberry has been recorded to grow as much as a foot a day.
26:38That's almost fast enough to watch.
26:41During the 1950s and 60s,
26:43drug addicts were treated in the island's newest buildings.
26:48The artwork on the walls hints at their plight.
26:54It's 1964.
26:56And if you're a heroin addict going cold turkey,
26:59this is not a pleasant room to be in.
27:02It's not a pleasant room to be in.
27:04It's not a pleasant room to be in.
27:06If you're a heroin addict going cold turkey,
27:09this is not a pleasant room to be in.
27:14The screen to my right is very thick
27:17and keeps the addicts inside from getting out the windows.
27:23The door to this room has a very narrow eye slot
27:27and a very large deadbolt.
27:29Once you're here, you're not getting out until they say you can.
27:37One piece of graffiti says,
27:39''Help me, I'm being held here against my will.''
27:43Many others detail names and borrows,
27:46places, streets from all over New York.
27:4950 years after people, no-one remembers their names.
27:56The breakdown of the building's defences is most evident here
28:00in the piles of plaster dust
28:02accumulated at the base of most of its walls.
28:05Plaster is the softest of the building materials here
28:09and so the first to go
28:11as the broken windows expose the interior to moisture.
28:18What's revealed underneath
28:20are the thick bricks used to isolate each room from the next.
28:24This building says to me that it was built for solitude,
28:28built for quiet.
28:30When the building was originally built,
28:33it was meant to be a tuberculosis sanatorium.
28:40Time has subverted the building's original purpose.
28:44What was originally a building meant for isolation and solitude
28:49is now a building that's a part of a cacophony of nature
28:53and that's what happens after people.
28:58The open air is not the only place on Earth
29:01where nature's tentacles are strangling what the humans have left behind.
29:07In shallow seas, once great warships are fighting a battle with ocean life,
29:12a battle they cannot win.
29:25It's 50 years after people.
29:31On the Hawaiian island of Oahu,
29:33the jungle has overtaken the roads leading into Pearl Harbour
29:36from nearby Honolulu.
29:40If you want to imagine what the roads of Honolulu would look like after people,
29:43all you have to do is come here to the old Pali Road.
29:46This one was closed in 1960
29:48and here is the vestige of the centre line
29:51and the vegetation from the mountain
29:53has encroached all the way to that point.
29:56And further on down the road,
29:58it encroaches from both sides
30:00until just a narrow winding path remains between them.
30:1065 years after people.
30:15Even the toughest built relics of war have started to decay.
30:21Along the coast of France,
30:23silent guns, barbed wire and iron beach obstacles are succumbing to rust.
30:31In the time of humans, this could already be seen
30:34at the imposing artillery emplacements of Pont du Hoc
30:37which overlooks the Normandy beaches.
30:46These emplacements are part of the Atlantic Wall
30:49built by the Germans during the Second World War
30:51to keep the Allies out of Northern Europe.
30:55On 6th June 1944,
30:57Pont du Hoc was pummeled by American forces
31:00during the massive D-Day invasion.
31:06The emplacement at Pointe du Hoc
31:08can be considered a military failure
31:11in terms of its ability to withstand the invasion from the sea.
31:14From a construction standpoint, it is a success.
31:17The structures are extremely durable
31:19but they are starting to undergo some deterioration.
31:24Bunkers and gun emplacements all along the Normandy coast
31:27were built of concrete with steel reinforcing rods.
31:30Constructed during wartime with the threat of imminent invasion,
31:34corners were inevitably cut.
31:39Seashells were often added to the concrete mix
31:42and in some cases the concrete was not given enough time to cure
31:45before the bombs began to fall.
31:50These weaknesses left the bunkers vulnerable
31:53not just to bombs but to future corrosion.
31:57Concrete typically deteriorates for a number of reasons.
32:00It can be reactive aggregates, reactive soil.
32:03It can be freeze-thaw cycles.
32:05And really none of those factors are present at Pointe du Hoc.
32:09The main problem in those structures
32:11has to do with the steel reinforcing itself.
32:15Moisture and salt in the air
32:17has entered the bunkers through pores and cracks in the concrete.
32:22This causes the steel reinforcing bars to corrode.
32:26They expand and crack the surrounding concrete.
32:32There's a wonderful example of what happens when steel corrodes.
32:35Right up here, you can see the concrete is cracked
32:38and the resulting deterioration of this steel reinforcing.
32:41You can see the expansive rust on the steel
32:44that causes the deterioration.
32:46That's very repairable, but in a life after people,
32:49that corrosion would continue, causing failure of that structure.
32:56The Romans used concrete to build some of their monumental structures
33:00long before the invention of steel reinforcing rods.
33:04This seeming weakness actually gives them an advantage
33:07in a life after people.
33:12In a life after people, concrete, if it's unreinforced,
33:15may actually survive longer.
33:17For instance, the Pantheon in Rome,
33:1920-foot thick lower walls,
33:21but it's an unreinforced structure
33:23and it survived for nearly 2,000 years.
33:26Whereas the structures at Pointe du Hoc
33:29have the reinforcing and the potential for steel corrosion
33:32that will probably progress in a life after people
33:35at a faster rate than a structure that's even 2,000 years old.
33:46It's 70 years after people.
33:52In Pearl Harbor, the ship that was once the pride of the US fleet
33:56is now under a cover of green.
33:59A blanket of shrubs and grasses consumes the decks of the USS Missouri.
34:04Vines creep up the topside structures
34:06and over the massive 16-inch guns.
34:10Although its mooring line snapped long ago,
34:13the Missouri hasn't drifted far from its crumbling dock.
34:17The mud of the shallow harbor bottom
34:19has kept the 45,000-ton colossus close to shore.
34:26Surprisingly, the Missouri is deteriorating faster
34:29above the waterline than below.
34:34We know this because of diving explorations
34:36to the nearby ruin of the battleship USS Arizona
34:3970 years after it sank during the surprise attack on Pearl Harbor.
34:49After decades underwater,
34:51the exposed parts of the Arizona have become heavily rusted.
34:57But below the waterline, the hull has been preserved
35:00by an army of multicolored sponges, feather worms,
35:03and corals.
35:06Basically, the incrustation is like a scab that covers the ship
35:09that actually protects the ship from corrosion,
35:12slows the corrosion rates down,
35:14so when the incrustation is present,
35:16the corrosion rates are much lower.
35:20And while marine life forms a protective layer
35:22on the Arizona's steel hull,
35:24the ship's wooden deck is covered with a layer of silt and sediment
35:28that offers its own protection.
35:30The wood-boring organisms,
35:32which would normally have deteriorated the deck,
35:34have been kept out,
35:36and so the teak decks are very well preserved.
35:38If you brush away the silt just a little bit,
35:40they're smooth and hard and look like they did on December 7, 1941,
35:44when the sailors were walking the decks.
35:49Seventy years after it sank,
35:51it was estimated that the Arizona still held 500,000 gallons of oil.
35:56Much of it trapped in the ship's fuel tanks and submerged compartments.
36:03Two gallons of oil leak from the ship every day,
36:06drifting to the surface like a slowly bleeding wound.
36:15Will this be the fate of the USS Missouri,
36:18or will it chart its own course of destruction
36:21in a life after people?
36:27And back in Denver, the biggest avalanche is yet to come.
36:40It's now 200 years after people.
36:45Stripped of its defenses, Denver's cash register building
36:49has repeatedly unleashed great avalanches onto the streets below.
36:57The next avalanche will not be of snow, but steel.
37:04In the time of humans, engineers at Colorado State University
37:08studied the many different ways skyscrapers can collapse.
37:14In this model, the heavy steel plates represent the floors of the building.
37:21The comparatively weak, thin wooden dowels
37:24represent the weakened state of a corroded frame.
37:28If an upper story collapses, it can cause a violent cascade.
37:40When the top floor of the building releases from the columns,
37:44its total weight is moving due to gravity.
37:47But by the time it hits the floor just directly below it,
37:52it has a force twice its own weight,
37:55and that effect would just increase and increase as the floors go down.
38:00A building as tall as the Wells Fargo building in downtown Denver
38:05could have this cascading effect perhaps 200 years in time.
38:22Outside Denver, on the Colorado prairie,
38:25the descendants of domestic cattle have carved out a new way of life.
38:31The future cattle would be a very, very different kind of animal
38:35than we see on the pastures and hillsides right now.
38:38It would be smaller, more fleet, more agile,
38:42able to escape from predators quite a bit more effectively.
38:46It would take on a lot of characteristics
38:49but would take on a lot of characteristics like deer.
38:55Even more striking are the herds of bison on the prairie.
38:59Before man hunted them to near extinction,
39:02there were as many as 60 million of these massive beasts roaming America.
39:06By the 21st century, that population had dwindled to 350,000.
39:14Supremely fit for this terrain,
39:16200 years without people has allowed their numbers to explode.
39:22Once again, the buffalo can roam.
39:31250 years after people.
39:36In Pearl Harbor, the decks of the battleship USS Missouri still rise above the waterline.
39:41But water is penetrating the hull.
39:45If you look on the waterline, you'll see a series of rivet heads
39:48and the rivets are the weakest link in the ship.
39:51As they rust, they'll fail and water will start entering inside of the tanks
39:56and it'll start flooding the ship.
40:00As it takes on water, the ship sinks deeper into the mud.
40:04The ship's deck will remain 10 feet above water,
40:07allowing the elements to continue to wear away her superstructure.
40:11How long will the Missouri's hull remain intact?
40:21Tests conducted on the USS Arizona in 2008 and 2009
40:25determined that its hull will take another 300 years to fully disintegrate.
40:30Built nearly 30 years later, the Missouri is a far more advanced warship.
40:37With an outer hull 17 inches thick in places,
40:40engineers estimate the ship could hold together for an astonishing 20,000 years.
40:49Becoming a new home for generations of tropical fish.
40:54A wrecked warship serving as an artificial reef is not a new concept.
41:01In 2006, the U.S. Navy intentionally sank the retired aircraft carrier,
41:06the USS Arisconi, off the coast of Florida.
41:10It took less than 45 minutes to slip beneath the waves
41:13and at roughly 9 o'clock in the morning,
41:15the ship sank to the bottom of the ocean.
41:19It took less than 45 minutes to slip beneath the waves
41:22and at roughly 900 feet long,
41:24it became one of the largest artificial reefs in the world.
41:28Within a matter of months, it was teeming with ocean creatures,
41:31including 38 species of fish.
41:40The Arisconi became known as the great carrier reef.
41:49Around the world, the armed and the defenseless soldier on.
41:54Some have shown surprising resilience.
41:56Others have suffered from hidden weaknesses that have brought them to their knees.
42:02On the bottom of the sea, along coastal bluffs and on desert flats,
42:07the battle quietly continues in a life after people.