A Non-Conspiratorial Explanation for "The Pod"

Could it be that a bomb, maybe a small bomb in the passenger compartment, has gone off inside the plane shortly before it impacts the tower? The pod might actually show the beginning stages as the central fuel tank explodes. This would explain why the pod produces it's own damage hole when the plane enters the tower-- it is a separate explosive device.

This of course doesn't explain how the wings slice through cement floors or the flash or the strange port wing distortion (see previous post), but it might MIGHT explain the pod.