Quote Originally Posted by vacuum View Post
It should be possible to use physics to determine what would make an impact like that. Figure out the amount of energy it would take to clear out that amount of cross section of building, then see if it's close to the energy of the plane upon impact.
Thank you for incorporating some slow brain thinking (the good kind) into the discussion. The picture Serpo posted is designed to elicit fast brain thinking, in order to form an instant conclusion, based on an assumption (aka it was a missile) without actually knowing for certain.