How world-famous landmarks would collapse if people disappeared

How long would it take for Big Ben, the Statue of Liberty or the Taj Mahal to crumble if people disappeared overnight? Life After People speaks with scientists, structural engineers and other experts to speculate about what the Earth would look like if human beings suddenly ceased to exist.

In London, one hundred years after people, the famous Big Ben clock tower is covered with vegetation. Its windows have blown out and chunks of decorative stonework have chipped away over the years.

The top of the 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 slowly rotting Big Ben's foundations. After 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.

200 years after people, with the collapse of the modern skyscrapers New York silhouette is a throwback to the great depression. 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 Building held that crown for less than a year before the Empire State Building surpassed it. Now the rivalry is over. The Empire State Building slips from the skyline. The Chrysler Building the first of man's skyscrapers to stand taller than one thousand feet is once again the tallest building in the city. But its reign won't last for long. The deteriorating columns can no longer support the floors. This is the critical point when a 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 the skyline of new york is now unrecognizable. (S1E1, S1E2, S1E4, S1E5, S1E6,)