After the tire burst, pieces of debris -- some weighing 9 pounds or more -- were projected outward, the investigators said. The projectiles damaged one or several fuel reservoirs on the left wing, causing "a very important gas leak and fire," said a statement from the Transport Ministry's Accident and Inquiry Office.
The statement shed more light on why the Air France Concorde crashed outside Paris on July 25, plowing into a hotel in flames and killing 113 people.
But it said the exact chain of events that brought the plane down remains to be determined, and that experts still must confirm their theory that the stray 16-inch metal piece was responsible. It also did not say where the metal might have come from.
Air France's five remaining supersonic Concorde jetliners have been grounded since the crash, though British Airways' fleet of seven Concordes continues to fly.