No word on any death toll at the Pentagon as of yet. However, all aboard the AA 757 are presumed dead. At this time, there are no known survivors from the aircraft.
From eyewitness accounts on several of the local TV stations (but WUSA 9, in particular), this is what happened:
The 757 came down low over one of the highways that surround the Pentagon, skimming it by just a few feet. A witness reported hearing suddenly something on the order of a "sonic boom", and then seeing the aircraft pass over at low height. Just before the aircraft reached the Pentagon, it banked hard right and collided with the ground, right wingtip first. (This is why you're probably not seeing long collision lines on the side of the Pentagon where the wings would have hit--they never hit there).
Again, an eyewitness reported an immediate cloud of white smoke upon collision, then a tremendous plume of black smoke that covered the entire area around the Pentagon.
The aircraft then cartwheeled into the Pentagon's lower three floors, driving all the way through the structure and into the open courtyard in the middle of the Pentagon structure. The debris is reported as being strewn all throughout the courtyard.
Several minutes later, perhaps as much as a half hour, the upper 2-3 floors collapsed from the lack of support underneath, leaving a full opening in the side of the building.
This is the best information that I have at this time. More to come.