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
"Life After People," man's most precious metals. How would gold prove his worth
in a future without humans? Can the properties
of steel protect it from its arch enemies? And what does a
mysterious gold mineral have to do with bringing
down the dinosaurs? Structures from an age of
steel will be changed forever. Welcome to earth, population 0. The great cities of mankind
were built on metal, financed by gold, constructed of steel. In the absence of man, these
metals seem well armored in the battle for survival. But what properties will allow
some to crumble and others to last? One day after people, in
the heart of Manhattan, the Federal Reserve
Bank of New York still guards the vast wealth
of depositors who will never return to claim it. It holds more than half
a million gold bars worth roughly $200 billion,
the accumulated wealth of some 60 foreign
governments and central banks. STEVEN A. ROSS: There is
more gold in the basement of the Federal Reserve
Bank in Manhattan than has been gathered
any other place on Earth and any other time in history. NARRATOR: The gold is stored
80 feet below street level. The narrow opened into the
vault is protected by a rotating 90-ton steel cylinder that
forms an air and watertight seal with the
surrounding 140-ton steel and concrete frame. STEVEN A. ROSS: The gold
lasts pretty much forever. The whole point of having gold
is that it doesn't corrode and doesn't tarnish. And there's nothing in nature
that can dissolve gold. NARRATOR: Gold is one of
the most non-reactive metals on earth, so when it's
exposed to air or water, its molecules resist
disintegration. But other metals in New York
City won't fare so well. Uptown from the
Federal Reserve Bank, the steel canyon
walls of Times Square are still a glittering
urban shrine. But the streets have
turned eerily quiet. In the time of humans, it
was one of the loudest places in a very loud city. Sustained exposure to
sound over 75 decibels was deemed dangerous
to human ears. Yet the ambient noise
here measured 80 decibels. Honking horns peaked
at 90 decibels, and a passing ambulance
siren screamed at 120. Now these sounds are silenced,
leaving just the 50 decibels home of thousands of
air conditioning units. GORDON MASTERON: A
world without people would be strangely silent. In many places, the dominant
sound would be birdsong. NARRATOR: Two days after people,
the New York City power grid is failing and so is the
trademark glow of hundreds of illuminated signs. These streets have
seen blackouts before. In 2003, a massive
east coast power outage plunged Times Square into
darkness for more than 12 hours But this time, the
blackout is permanent. In the light of day,
New York's urban jungle is prowled by
creatures unaccustomed to fending for themselves. The horses that once
carried police officers and pulled Central
Park carriages must adapt to a life with
no humans to care for them. In a world of
concrete and steel, can these horses survive? 875 miles west of New York City,
the breaking point of metal is about to be tested. With a dozen breweries
including Anheuser-Busch, St. Louis was known as
America's brewing capital. In the city that once quench
the thirst of a nation and the world, 3 million
kegs worth of beer continue to ferment in several
thousand massive steel vats. MARC GOTTFRIED: This is a
30-barrel fermentation tank. It holds 60 kegs of beer, and
this is what's inside this tank floating towards the top. It's made of yeast,
hot particles, protein, and nitrogen. NARRATOR: Inside these
fermentation tanks, yeast is used to turn
sugars into alcohol. Carbon dioxide is given
off as a byproduct, which creates increasing
pressure in the tank. MARC GOTTFRIED: If people
were gone on day one, the fermentations would
go about as normal. As soon as electricity
failed then the cooling failed
with it, the tanks would begin to rise
in temperature. In the St. Louis
summer, temperatures can rise over 100
degrees very easily. The heat rising the
brewery will only aggravate these
fermentations, make them more and more violent. NARRATOR: Automatic safety
release valves normally prevent pressure from
getting too high in the tank. But fermentation also creates
something called krausen, a meringue like residue which
rises to the top of the tank. The extra heat
triples the amount of krausen rising to
the top of the tank where it clogs the
pressure relief valve. MARC GOTTFRIED: If
this were to happen, it could cause a
catastrophic failure over the course of 36 hours. NARRATOR: In 2009, a
fermenting VAT explosion tore a 30-foot hole in the
roof of a New Orleans brewery. In St. Louis only 36
hours after people-- [explosions] These violent eruptions
blast holes in roofs as they unleash their
intoxicating contents in golden flows. Back in New York City, the
problem isn't beer but water. Without power, the 700 pumps
that once emptied the subway system of an average of 13
million gallons of water a day are no longer operating. The tunnels are already
beginning to flood. It's six months after people. New York City is dark except for
a strange glow in Times Square. Installed in 2009,
this illuminated beacon of the human past is a billboard
that doesn't rely at all on the municipal power grid. Ninety percent of
the sign's power is generated by
16 wind turbines. The rest comes from an
array of 64 solar panels. The sign's power plant
generates enough electricity to power six houses for a year. The turbine's blades were
designed to resist freezing in winter and to automatically
slow in the face of hurricane force winds to prevent damage. The sign should keep
glowing for years unless something
unexpected happens. One year after people, the
plaza at Rockefeller Center in midtown Manhattan is
still a gathering place. Only now, it's animals
that congregate here. One of the changes that
would take place in New York if people were out of the way
is that the native animals would move back in. There are already a
tremendous population of deer in the suburbs of New York. We may see deer right in
the heart of the city. NARRATOR: In the time of
humans, this concrete chasm was a plaza that transformed
into an artificial ice rink every Christmas. This winter, mother nature
provides her own ice. STEVEN A. ROSS: What would
happen is water would freeze during the winter on the rink
area itself and would pile up. And during the spring,
the little iceberg would melt and continue
to add to the water underneath the
buildings themselves. And that would begin to
deteriorate the foundation. NARRATOR: In the
springtime, the sunken plaza becomes like a giant flower pot. STEVEN A. ROSS: The ice
rink would definitely become a garden early. It would be wet
more of the year. That's good for growth. NARRATOR: Lording
over this urban garden is the statue of Prometheus,
a figure from Greek mythology credited with creating mankind. He now presides
over the destruction of what man has created. The Prometheus statue itself
would survive very, very nicely. It's bronze. It's gilded. And for the first
five or 10 years, the gold gilding on top of
it would continue to shine. That's what gold does. But it's a very,
very thin layer. The rain, the hail, the
dust that blows around would eventually scour it
down to the original bronze. NARRATOR: One year after
people, the slow decay progresses in silence. But soon, the sounds of crashing
steel and stone from above will turn Manhattan into
an island of destruction. And something in their bones
will bring down the dinosaurs. Three years into a
life after people, every street corner in New York
City is dark except for one. But the wind and solar power
billboard in Times Square finally flickers out. It's not for lack of
power, just a simple matter of having nobody to
change the light bulbs. Meanwhile, the survivors of
the urban horses that once patrolled Times Square and
pulled tourists around Central Park have fled the city. But can they possibly
survive for long in a life after people? FRANK LOWENSTEIN: The horse
is an animal of the plains. It's largely a grass
eater, and what's more it's escape mechanism from
predation is largely to run. It's also a pretty good
fighter if it needs to be. So the horses here
in New York City, they have the potential
to go wild again, but they need certain things. They need grass. They need open space to run. Golf courses are going to look
great, all those suburban yards around New York. NARRATOR: But soon, the
yards and golf courses will turn into forests,
which don't provide the grassy grazing
environments that horses need. In order to survive,
these horses need to find a suitable
habitat in a hurry. Surprisingly, their best bet
is to head for the beach. The grassy barrier islands
of the Atlantic coast have already proven
their ability to sustain herds of wild horses. In the time of humans,
several hundred of them made their home
on Assateague Island just off the coast of
Virginia and Maryland, the descendants of
horses brought here by man 300 years earlier. FRANK LOWENSTEIN: No reason why
there shouldn't be wild horses on Long Island as well. But it's a question
of are the horses, if the police horses or
other horses that escape, are they going to find
those places in time. NARRATOR: Ten years after
people, one of the most unusual steel structures,
the Gateway Arch, still stands along the
Mississippi River in St. Louis, little change from
the day humans last packed its observation
deck high above the river. At 63 stories, it is the
tallest structure in the city, and it might prove to
be the longest lasting. Although it's said the architect
Eero Saarinen designed it to stand for 1,000
years, its slender form looks vulnerable in
a life after people. Unlike a skyscraper, the arch
doesn't have a steel skeleton. Its strength is derived from
double walls of stainless steel plates filled with concrete. GORDON MASTERON:
Stainless steel corrodes at a very, very slow rate. NARRATOR: The surface
of the stainless steel is covered with a
film of chromium oxide that can resist
corrosion for decades. BOB MOORE: If people
suddenly died off, I think I would probably
stand for a long time. There's no water intrusion
into the structure at all. With no water getting inside
of it, no rust forming, there'd really be no reason
why anything would happen to the structure itself. NARRATOR: The arch remains
as the gateway to the west, at least for now. At Rockefeller Center,
the walls of the buildings have undergone a
strange transformation. STEVEN A. ROSS: These
seams between the blocks of the limestone that
coats all these buildings, those seams would catch a lot
of seeds and a lot of dirt, and even 20 or 30 years
out, you would probably see a green grid begin to
spread out over these buildings. NARRATOR: Plants have already
shown a relentless drive to colonize places in New York
where they were never supposed to be. This is the High Line, an
elevated railroad track that runs for 22 blocks
along Manhattan's west side. It was completed in
1934, allowing trains to make pickups and deliveries
directly inside warehouses and factories from the
meatpacking district to Hell's kitchen. But rail traffic
declined in the 1950s as more cargo was being
transported by truck. The last trains rumbled along
parts of this line in 1980. STEVEN A. ROSS: Here you have a
structure that's predominantly steel, it's in Manhattan,
but nobody walked on it. Nobody paid any attention to
it except for the wildlife and the wild plants of the city. NARRATOR: This ribbon of
wilderness high above the city streets is proof that the
Big Apple will turn green very quickly in the
absence of humans. Thirty-five years after people,
the mansion-lined beaches along West Hampton, a Long
Island getaway for New York's rich and famous, no
longer provide an escape from the troubles of the city. The opulent homes were
always perched precariously on the sea. Many houses were even built
on the barrier islands that separated the mainland from
the pounding Atlantic surf. In the 1990s, a series
of Atlantic storms breached the barrier
island of West Hampton, destroying many homes. After that, the US
Army Corps of Engineers rebuilt the barrier island and
made sure it was constantly fortified by dredging
sand from the sea bottom to build up and
reinforce the beach. LYNN BOCAMAZO: Right
now we're on the dredge, and we can see the drag
head, which is actually very similar to a
vacuum cleaner head. It just vacuums up the sand
above the ocean bottom. A sand slurry is pumped from
the dredge onto the beach. When it gets onto the beach,
it is reshaped by earth moving equipment on the beach. NARRATOR: Every four years,
the Army Corps pumped up to 1 million cubic yards
of sand onto the beach. Now, without the Herculean
effort of humans, the mansions of
the rich and famous fall victim to the waves. LYNN BOCAMAZO: If there were
no humans to do some beach and ocean projects, we
expect that tens of thousands of houses would be damaged,
and the low lying areas of Long Island would be flooded. Fifty years after people,
dinosaur skeletons remain standing as
relics of a time long before humans
walked the earth. Their metal armatures have
kept them upright for decades, but there's a disease
growing in their bones. It's called pyrite disease named
for the mineral pyrite, also known as fool's gold. It forms during the
fossilization process as bacteria trigger a chemical
reaction that replaces soft tissue with hard crystals. JAN ZALASIEWICZ: Fool's gold
is one of the common minerals that forms around
decaying organisms and that we find around fossils. A lot of the fossils I work on
are literally golden in color. NARRATOR: If fossils are kept
under the right conditions, the pyrite inside
remains stable. But in the presence
of humid air, the mineral reacts with
oxygen and expands. These growing crystals
crack the bones from within. In 1999, the
triceratops skeleton, which had been on display at
the Smithsonian Institution for almost 100 years had to
be dismantled and conserved, its bones ravaged
by this disease. Only half a century after
people in the world's great natural history museums,
the reign of the dinosaurs is coming to an end. High above New York
City, the stainless steel crown of the Chrysler
Building still shimmers. In the time of humans, the
building's low maintenance steel only had to be cleaned
twice in a span of 76 years. On the 61st floor, eight
stainless steel eagle gargoyles keep watch over the
city, constantly buffeted by high level winds. STEVEN A. ROSS: The
Chrysler Building is particularly
exposed to the wind because there's not a
lot of tall buildings to the east of it. The gargoyles are not really
fastened super tightly to the structure
of the building. They're an add on. They're basically
bolted into place. NARRATOR: Its connection to
the building corroded, one of the wingless eagles takes
its first and final flight. Around the world, the sounds
of crashing steel and stone become more frequent
as the years go by. It's a reality that is
already tearing apart this once thriving spot in the
Nevada desert whose founders intended it to rival
the city of Chicago. And its soon to be a
reality in our great cities where some structures have a
surprising flaw that can kill them before their time. Ninety years after people is
enough to ravage even cities that were built to last. It's a future that
has already happened in this mysterious site. While modern cities
are built on steel, this one lived and died by gold. This is Rhyolite, Nevada, a
former gold mining town located 120 miles from Las Vegas
in the unforgiving desert landscape near Death Valley. When gold fever struck the
Nevada mountains in 1904, Rhyolite's population of two
miners jumped to 1,200 people in just six months. Some found great success. In its first three years,
the largest mine in the area produced over $1 million
in gold, the equivalent of more than $24 million today. These riches fueled the
construction of a town that the city fathers
hoped would rival Chicago. By 1908, there were as
many as 8,000 residents. GARY SPECK: This is the
Rhyolite Railroad Depot. It was built 1908. It's one of the first things
that people would see when they would come into the town. Standing here today in
this quiet ghost town, you can almost hear the sound of
that coal-powered steam engine coming up the hill, the black
smoke pouring out the coal stack. And as the people disembark
onto the steps of the station, you could almost hear
their excited shouts and cries as they come down
to visit what they hope is going to be a golden future. NARRATOR: Despite the
early promise of the mines, much of the most
valuable ore in the area proved too difficult
to extract, and a nationwide financial crisis
dried up the capital needed to sustain the hunt for gold. By 1910, the boom was over. The town was left to die. Rhyolite may look like a
classic Old West ghost town, but the structures here
tell a unique story. This is the Cook Bank
building, once the crown jewel of Rhyolite. It guarded over
$200,000 of hard earned wealth, which would be the
equivalent of roughly $4 million today. In its prime, the bank had
marble stairs and stained glass windows. GARY SPECK: It was built
right at the peak of Rhyolite during the boom time,
and this whole valley was covered with houses
and cabins and tents. NARRATOR: If it had been built
of wood, like most structures of the era, the walls would
have collapsed long ago. But this was one of the
earliest multi-storey buildings in the west to be constructed
of reinforced concrete, a technique that had then
been in use for only 15 years in the United States. Built to last, the
concrete has stood tall against the ravages of time,
but time is running out. GARY SPECK: When you look at
these buildings like this, all this massive concrete structure,
it's only 100 years later, and we're sitting here looking
at a shell of a building that's crumbling to the dust. Another 100 years from
now, this building will be nothing but
gravel and sand. NARRATOR: The enemy in
Death Valley isn't moisture. This is one of the
driest places on Earth. Located in the mountains
rather than the valley floor, Rhyolite still averages
only about six inches of rain per year. What there is plenty of
here is wind and sand. The abrasive grinding
action of the desert wind is like a sand blasting tool. The particles erodes surfaces
and penetrate into cracks. The concrete de-laminates
causing layers to separate from within,
and the structure crumbles. STEIN STURE: As you can
tell, it's a dangerous place. The building has been
standing here for 100 years. And if you look up, you'll see
that the building is almost ready to topple
under its own weight. NARRATOR: Man
helped nature along in its destruction of Rhyolite. People began scavenging
wood supports and other useful
materials that were scarce in the remote desert. STEIN STURE: The floor joists
were sawed off and removed from the building soon after
the building was abandoned. And once the floor
joists disappeared, the building surfaces are
free to deflect outwards. And to fit that process in
place, the building's integrity is at stake. NARRATOR: At the town's
general store where miners once came to buy the
tools of their trade, the disappearance of its
internal wooden structure has hastened the destruction. Even glass, a substance
made from sand, is a primary building block
in one surviving home. The Bottle House was made from
30,000 empty whiskey bottles. Although the house has been
restored several times, including in 1925 for use
in a silent film, the glass itself is biologically
inactive and does not corrode. Rhyolite's ambitious founders
hoped to build an enduring metropolis in the desert. Instead, after 90 years, it is
on the verge of vanishing off the map. GARY SPECK: This shows
that you can set up a city and it will crumble
down and go away within a couple of 100 years. NARRATOR: A century
after people, all cities around the world will take
on the look of the abandoned towns of the west. In New York, the skyscrapers
are ghostly towers, and a change made in
the 1940s will soon determine this strange
new shape of the skyline. One hundred years after people,
the sound of snapping steel reverberates down the corroded
canyons of New York City. The cables of the suspension
bridges connecting Manhattan to Brooklyn and
Queens are failing. The roadway of the
Brooklyn Bridge is held up by just over 1,000
vertical suspender or hanger cables, each about the
thickness of a human wrist. Each cable is made up of
seven strands of steel twisted around each other, a total
of 100 miles of steel in every cable. The cables are galvanized,
covered in a protective coating of zinc, which corrodes much
more slowly than the underlying steel. ALAN W. PENSE: This is the
wire from an existing or cable from an existing
bridge, a hanger cable. And you look at the
condition of the cable. You're going to see the
paint is peeling off, and you can see that there are
places where there's red rust. That means that the coating on
these wires, which are mostly galvanized coating, the
galvanizing is failing. And so now you have a
wire that's going to rust, and you may have failures by
fracture of individual wires. Once you've broken
enough of the wires, then you begin to break
wires as kind of a cascade. And you'll see them fray,
and then the rope will fail. NARRATOR: Just upriver from
the Brooklyn Bridge, the city's most adventurous commuters once
relied on another steel cable structure to get
them into Manhattan. The only thing holding up
the Roosevelt Island Tramway is a pair of nearly 2-inch
diameter wire ropes. The weak point is the spot where
the cables cross over the steel support towers. RENE B. TESTA: Especially
where the cable goes across over the saddles and
at the terminals, the cable is bent back and forth
as the tram goes across it. So you tend to get some
fatigue loading in the cables, and that is what actually
uses up the life of the cable. NARRATOR: In the time
of humans, the cables were shifted roughly 100
feet every five years to keep any one point from
being in contact with the towers for too long. Now even though the tram hasn't
moved along the cable for 100 years, wind has continued
to buffet the tramway, causing stress on the
wires near the towers. They snap, and the tram car
plunges 250 feet into the East River. One hundred fifty
years after people, at Rockefeller Center
where humans once had to truck in a tree to
celebrate the holiday season, the greenery is now
on permanent display. The skyscrapers that
made New York famous have transformed into
vertical ecosystems. FRANK LOWENSTEIN: Towards
the bottoms of the building, you'll begin to get rubble
and soil accumulating. Then you'll get things that like
those sort of dry environments, things like oak and hickory
and a wide variety of grasses. The higher up you go, the
more wind you're going to have and the drier it's going to be. So those are places
where the plants that colonize the outside
of the building are going to be cliff dwellers. NARRATOR: One
hundred fifty years after people signals
the beginning of the era of the great building
collapses in New York City. Surprisingly, it's
the newer buildings that are crumbling the fastest. While the walls
of older buildings had to be strong integral
parts of the structure, new types of steel developed
in the mid 20th century allowed most of a
building's weight to be carried by
the inner columns. So most of New York
city's postwar skyscrapers were built using a glass and
steel curtain wall technique in which the outer
walls just form a lightweight protective
skin of steel and glass. STEVEN A. ROSS: One of the big
complaints New Yorkers have with newer buildings
is that they all leak. Well, if they all leak while
we're maintaining them, they're all going to leak a
lot when we're not maintaining them. And so the most modern buildings
would actually go first. It's the buildings that were
built up through the 1940s that would last the longest. NARRATOR: Two hundred years
after people, with the collapse of the modern skyscrapers,
New York's silhouette is a throwback to
the Great Depression. Both completed in the early
1930s, the Empire State Building and the
Chrysler Building once vied to be the tallest
buildings in the world. The Chrysler held that
crown for less than a year before the Empire
State surpassed it. Now, the rivalry is over. The Empire State Building
slips from the skyline. The Chrysler Building
the first of man skyscrapers to stand
taller than 1,000 feet is once again the tallest
building in the city. As before, its reign
won't last for long. The deteriorating columns can
no longer support the floors. GORDON MASTERON: That's
the critical point where the skyscraper becomes
on the verge of total collapse. Several columns buckling
in a single floor, allowing one floor to descend
rapidly to another level below, would be sufficient to
trigger a cascading collapse. NARRATOR: The skyline of New
York is now unrecognizable. In fact, very few
tall structures remain standing in the
cities of the world. One of the exceptions is The
Gateway Arch in St. Louis, but a small park added to the
structure at the last minute holds the key to
its destruction. For 250 years after people,
St. Louis's Gateway Arch has worn its stainless
steel skin as armor against the dragon's
breath of corrosion. But stainless steel
isn't invincible. GORDON MASTERON: It
doesn't last forever. The mechanism for final
failure will probably be around the center
of the arch at the top. That's its thinnest point. NARRATOR: The thinnest points
are the two sections that form the so-called keystone,
their steel triangles 17 feet long by 18 feet high. They were the last
pieces to be installed. The keystone is so critical
to the structure's stability that until it was inserted,
a temporary stabilizing trust had to be used to keep the
two legs from collapsing. Before the pieces were lifted
into place on October 28, 1965, a Roman Catholic priest and
a rabbi blessed the keystone. Now the prayers of man
are of little help. The keystone buckles and
drops from the structure. BOB MOORE: The two
legs of the arch would not be able to
stand on their own, and they would fall
down to the ground. NARRATOR: The first
250 years after people have seen the skylines
of our cities crumble. Now, the ruins will be swallowed
up by water, soil, and plants. One thousand years after people,
New York's skyscraper canyons are now just canyons. Rivers flow where
taxicabs once rolled. FRANK LOWENSTEIN:
Their course is going to follow what
used to be the streets and are now these
sort of pseudo canyons at the bottom of these
strangely shaped hills that are the rubble left
of the skyscrapers. Ten thousand years after
people, on the New York shoreline wanders a pack of
wild horses, the descendants of the urban equines
that thousands of years ago protected and entertained
the humans of New York City. The high salt content in
their seaside food supply means that they have to
drink twice as much water as their domesticated
ancestors once did. And the grasses here are
so deficient in nutrients that the horses have evolved
a shorter stature in response to the poor quality
of their diet. Still they have survived. Buried in the ground
beneath their feet, a corroding steel crypt holds
tight to its precious contents. Once 80 feet below street level,
the Federal Reserve gold vault is now hundreds of feet
underground and inundated with water from rising seas. Inside, the largest stockpile
of gold ever assembled on earth remains well-preserved. JAN ZALASIEWICZ:
They're underground. They're encased in steel. Now, steel will be much
less happy underground. If you look at archaeological
iron steel implements, on the surface they rust. Underground they tend
to pit and corrode. NARRATOR: Although the steel
will eventually corrode, the gold bars themselves should
last not just for thousands of years but even millions. STEVEN A. ROSS: When the
future archaeologists find it, they're going to wonder about
the culture that built such an amazing temple and sanctuary. NARRATOR: The 24-karat gold will
live on as a precious metal. Once mined, molded,
and guarded by humans, now we turn to the earth
in a life after people.
I remember when these things first aired, that was when the history channel was morphing from appealing broadly to people with an interest in history of all types to the All-Hitler–All–the–Time channel, before turning into the Aliens channel, and finally the junk dealers’ network.