If only one plane had been hijacked and hit one of the towers it seems possible that the cause of death of any victims would have been listed as accidental.
crashing more than one plane was probably the muzzies biggest mistake. Crash just one and it would have been dismissed as an accident.
In the week following 9-11 there was another fatal plane crash near NYC, the airliner from the Dominican Republic. It was determined to be accidental....but many people suspected it was a terrorist act, but the government wanted to cover it up because the country couldn't handle another terrorist act at that point.