Also,

The plane that went down in PA went down at approximatey an 80* angle. That is nearly straight down. That plane desintegrated on impact, and then burned, and I can validate:

Several years ago a 64 passenger American Eagle Express crashed in rural Indiana. My Father, also a Volunteer Firefighter; in that locale, was at that scene, and the largest body parts they found intact were fingers and toes. They had a very similar scene in PA, considering the size and speed of the that plane.