I have heard that theory at many times as well. But since I have been to ground zero several times with my dept, I found myself drawn to the televisions n ews plus radio broadcasts to learn of the situation. I have only heard such possibilities through the mouthes of civilians that were not witnesses. I would personally rather keep these people in my mind as heroes, and dont see why anyone would question it. The U.S. did not give the air force permission to shoot down any more non-coherent aircraft until after the plane had already crashed in Pennsylvania.