Here is a hypothetical scenario for you.
Imagine that you are in a slowly, but inevitably collapsing building. That is to say, that the building is falling down slowly...and that it will fall down.
The point of it falling down slowly, is that if a part of the building fell down before another part, then it would allow for the following scenario:
You are on the ground floor of a building. The building starts to fall down slowly but inevitably. Would you have a better chance of surviving the building by just ducking and covering, jumping underneath a nearby table, or jumping into already fallen debris?
Putting aside the morbid nature of such a scenario, i was thinking it would make the most sense to jump into the already fallen rubble. My thinking is that it is made of strong material (The wall, and roof) and you would have a much better chance of surviving the heavy falling debris there, then under a table, or by yourself.
The down side would be that you will be alive underneath all the rubble of the building, and you would have to wait a while before being rescued.
but maybe I havn't thought this through all the way. What do you think?