These are just simulations done in a computer of what might happen if a plane hit a structure such as the Pentagon. Just because it can be simulated doesn't make it fact in the real world. If you were the government trying to cover something up, don't you think you'd do all of these things to make a convincing presentation? There has to be SOME film somewhere of this plane in route to the Pentagon. You can't fly a plane over one of the biggest cities in the world without some camera catching it on tape. Ps: Josh made an excellent point. How can you get DNA samples out of a 2,500 degree fire? If it is hot enough to melt some metals and vaporize others, how in the world could DNA withstand that and still be collectable?