One of the structural engineers at work told me he knew a secret...and he knew exactly why the buildings fell.
I held my breath and waited to be enlightened by his theory.
He told me “They flew f#ing airliners into them!”
That about sums it up.
You Have Shear, big massive object hitting the steel tooth picks that hold it up, cutting through steel core that really holds it up.
Then you have a lot of heat that causes the tooth picks to deform and collapse. (See ASME for details)
Then you have commies................