The key insights seem to be: 1) Despite the chaos, the debris of a collapsed building can be mapped to the structure as it was when standing. 2) All sorts of

The key insights seem to be: 1) Despite the chaos, the debris of a collapsed building can be mapped to the structure as it was when standing. 2) All sorts of information can be used in figuring out where you are - the breed of a dog corpse, a scrap of paper with the name of a victim's rabbi... 3) Be skeptical of secondary sources (estimates of the number of victims...) 4) Bureaucrats will be obstructive just by doing their job as if nothing has happened (we can't tell you that...) One thing that was not mentioned, but which I imagine was part of the calculus, is what people are likely to do at the first sign of trouble (in this case, noise and shaking) - head for the stairs, go to the window, wait for it to stop...