Yes I did and upon further checking I was mistaken as there were some cores that had 4.91 inches of thick steel.
Actually as usual your thinking is flawed as conservation of momentum would not explain why the lower floors collapsed with such little resistance but would show that they should have slowed the decent but it did not – so if you have any inkling of physics then something prevented that from happening. Now it doesn’t take even a slow learner to figure out what would prevent that from happening.
Silence is golden but duck tape comes in several colors.