You must add the acceleration due to gravity in the force equation otherwise you are ignoring conservation of energy.
The kinetic energy that was input to raise the structure against gravity over a very long time must be released to balance the latent energy rereleased as kinetic, in a very short space of time. When you release vast amounts of energy in an extremely short space of time guess what you get. .
There is a big difference between static load and dynamic load. A floor designed for e.g. 20Mpa stress is only as strong as the aviation fuel detempered steel props that hold it and the weight of a floor slamming the one under it at 9.8m/s2, then combining to slam the second floor under, combining to slam the third, etc, etc all defining what.we saw.
I've personally seen a basement column capital punctured by the weight of the floor(s) above, the only thing saving it exploding, a pilaster on the perimeter. The forces are incomprehensible to some engineers let alone laymen looking to arithmetic to solve complex equations.
The only 911 conspiracy we should be concerning ourselves with is the deliberate anti western forces that would send us back to join them in the stone age IMO
