"I don't know. I think we're getting hijacked." That was the terrifying message from a brave flight attendant on board the American Airlines plane minutes before it flew into the World Trade Center.
It's part of just-released 9/11 tapes never heard in full before. 9/11 terrorist ringleader Mohammmed Atta is heard addressing passengers:
Hijacker: "Nobody move! Everything is okay. If you try to make any moves you will endanger yourselves and the airplane. Just stay quiet."
But flight attendant Betty Ong secretly called American Airlines headquarters from a phone in the rear of the hijacked plane.
Flight attendant: "The cockpit's not answering. Somebody's stabbed in business class and I think there's MACE. We can't breathe."
Moments later the plane crashed into the World Trade Center.
The tapes convey the chaos as the tragic events unfold on radar screens.
Air traffic controller: "We have a problem here! We have hijacked aircraft headed towards New York and we need you guys to, we need someone to scramble some F-16s or something up here to help us out."
Controllers watched helplessly as the second hijacked plane hit the World Trade Center.
Air traffic controller: "Wow! Another one just hit it hard. Another one just hit the World Trade. The whole building just came apart!"
The drama switched to Washington as a third hijacked plane dove into the Pentagon. One controller called for the President to be immediately informed that America was under attack.
Air traffic controller: "I don't know but somebody better get the President. This is not good!"
Air traffic controller: "And I have the President airborne."
Vice President Dick Cheney personally ordered fighters to shoot down passenger jets if necessary.
This is how the Air Force received the historic order:
Mission crew commander: "You read that from the Vice President, right? The Vice President has cleared us to intercept tracks of interest. Shoot them down if they do not respond."
A pilot reports seeing United 93 moments before it crashed in Shanksville, Pennsylvania:
Air traffic controller: "United 93 was waving its wings as it passed the VFR aircraft. They don't know what that means."
It was hijackers flying erratically as the heroic passengers tried to take back the plane. Then...
Air traffic controller: "There is a report of black smoke in the last position I gave you."