Originally Posted by KILLER_CLOWN
I would say it's 100% impossible for a group of cavemen to have pulled this off, Norad stand down says HI - Thanks Darth Cheney.
It WOULD be 100% impossible for cavemen to do it. Cavemen didn't do it.
It wasn't hard at all for a bunch of 21st century terrorists to highjack a couple of planes and crash them.