Leaked Video of Cruise Missile Hitting Pentagon on 911, page-4

That's the really awful part when you think about it.
Nothing about the damage to the Pentagon indicated it was hit by a large passenger aircraft but that aircraft and all the passengers and crew have never been seen again. If it didn't hit the Pentagon then it must have landed somewhere else and been destroyed along with everyone on it.
An operation like that, the level of secrecy and the people involved is truly chilling.