Eyewitness accounts
Omar Campo, a Salvadorean, was cutting the grass on the other side of the road when the plane flew over his head.
"It was a passenger plane. I think an American Airways plane," Mr Campo said. "I was cutting the grass and it came in screaming over my head. I felt the impact. The whole ground shook and the whole area was full of fire. I could never imagine I would see anything like that here."
Afework Hagos, a computer programmer, was on his way to work but stuck in a traffic jam near the Pentagon when the plane flew over. "There was a huge screaming noise and I got out of the car as the plane came over. Everybody was running away in different directions. It was tilting its wings up and down like it was trying to balance. It hit some lampposts on the way in."
A pilot who saw the impact, Tim Timmerman, said it had been an American Airways 757. "It added power on its way in," he said. "The nose hit, and the wings came forward and it went up in a fireball."