Here's an account from an eyewitness to the attack on the World Trade Center. This person was just a few blocks from the horrible scene.
I heard a second extremely loud crash . . . the scene was unimaginable. The World Trade Center building had collapsed into itself, shooting a large black cloud of smoke into the sky. I watched while bodies fell from the windows, as the building came down in a giant plume of smoke.
Then someone yelled to look out the front window -- and a sight met my eyes that put the first thought in my mind that I might die. Smoke was slowly moving down the street toward us as people ran screaming away from it.
The account is absolutely terrifying. It was written by a 13 year old child.