How do buildings collapse in a downward direction during earthquakes?

Question

Example: [https://youtube.com/shorts/t1nC0AOP_X4?feature=share](https://youtube.com/shorts/t1nC0AOP_X4?feature=share)

I don’t get it. The Physics of it. And also how would one prevent this?

In: 6

Answer 1

Note how the bottom floor collapsed with the upper floors structurally stable until they slammed down. You want buildings to collapse downwards rather than sideways, but they shouldn’t have collapsed at all. Those open-floor buildings were not built to code and had upper floors extended over basically air.