In 2009, an entire 13-story apartment building collapsed in Shanghai.
As you are probably aware, multi-story buildings are massive. They aren’t just tall; they are heavy. As such, one would expect the death toll to be near catastrophic (especially in a tall building that is capable of holding a number of people. Fortunately, the building was unoccupied at the time of its collapse, so the death toll was much, much less than what it could have been.
In fact, remarkably, only one person died as a result of this collapse. But that’s not the only remarkable thing about the building’s demise. Just look at how it fell over — it looks like it was cut clean from its foundation.
How can this be? How can an entire building just tip over like a tree?
The answer is rather simple. You see, when buildings tip over, they generally suffer huge stresses in terms of bending. Almost invariably, this causes them to break into pieces. Obviously, it is a lot harder for the building to stay perfectly straight as it is tipping over.
Ultimately, the pressure placed on different sections as a result of the tipping causes the breakage. Technically, this has a lot to do with angular momentum, but even without it, one can easily understand that the top part needs to move a lot faster than the bottom part. In short, as it falls, one part pulls at the other part, and the whole thing breaks (the mathematics is just so much nicer with angular momentum than calculating the internal stresses bit by bit).
So, why didn’t this building break apart?
The plan called for underground storage compartments to be built. This caused one side to lose ground support. Add to this the increased rainfall, and that there was a build up of excavation on the opposing side, and you have a recipe for disaster. As it turns out, the building itself was really sturdy, but the foundations were not. Two men were sentenced to life in prison for this collapse. The men were charged with graft, embezzlement of corporate funds, and causing a serious accident.