As gruesome,and horrific as it is to contemplate..my reasons are multiple and based in simple Physics,but probably best answered by the 1500+Distinguished Scientists,Architects,Demolition Experts,who contributed to the Canadian Commission on the events of 9/11.
ill believe the official story when they release more than 3 frames of blurred video purporting to show an aircraft hitting the pentagon, why did they confiscate all the video footage from the surrounding areas, gas stations, motorway cameras and all the cctv footage from one of the most secure buildings in the world.