I copy/paste a post on another forum about what happens if you drop something on the WTC1 structure:
Quote
Let's make a simple experiment; you need a hammer with a 1 kg solid head and a 0.1 m steel bolt with cross area 0.0001 m² (it weighs 0.078 kgs). Thus the hammer is 12.73 times heavier than the bolt.
You put the bolt upright against a solid support and then you drop the hammer head against the bolt from various heights h = 0.1, 0.2, 0.3, 0,4 m, etc.
What happens? Well, for certain the bolt never collapses at impact. The bolt deforms elastically and the hammer bounces.
Try to drop the hammer from h = 1, 2, 3, 4 m, etc. Same result! Ok, maybe some plastic deformation at the top drops + deflection of the hammer head.
****ing strong bolt! OK, the uniform density of the bolt is 7.8 (like the hammer's density) and it is 43 times more than the uniform density of WTC1.
Let's replace the bolt with something more fluffy - lighter. What do we have? A roll of toilet paper with diameter 0.1 m and height 0.1 m. Same uniform density as WTC1.
OK, I put this roll of toilet paper on my solid support and repeat the experiment using the hammer as drop weight. What happens? My children audience was very excited.
Well - dropping the solid steel hammer head on the little paper roll from 0.1-0.4 m just produced bounces! No collapses of the paper roll.
Let's drop it from 4 meter the audience yelled. Guess what the result was?
Quite difficult to collapse a toilet paper roll with a hammer, though.
But to be fair! Whatever is alleged to impact WTC1 lower structure after dropping from above has the same density (and built in associated strength). The upper part of WTC1 has the uniform density (and the built in strength - uniformly distributed though) of a roll of toilet paper.
It will not cause any global collapse, ever.
Reason is that the available strain energy, SE, of the bolt or the paper roll to absorb kinetic or potential energy, PE, applied/released from above is too big. SE>PE.
NIST, in its infamous WTC1/2 report suggested SE<PE, maybe a typing error (?), but hopefully Obama will fix it. It changes everything, of course, but maybe "we can" accept that?
Un-quote.
I can assure you that it is difficult to destroy a structure by dropping something on it.