The FBI has released previously unseen pictures of the devastation at the Pentagon on 9/11.
Hijacked American Airlines flight 77 crashed into the building in the 2001 terror attack, killing 187 people.
The images show debris from the jet strewn on the floor, rescue workers searching for survivors and the extent of the damage to sections of the building.
Almost 3,000 people were killed in the 9/11 attacks, which were claimed by al Qaeda and its then leader Osama bin Laden.
Hijackers seized control of passenger jets and crashed them into the North and South towers of the World Trade Center in New York and the Pentagon in Arlington, Virginia.
Another flight, United 93, was also taken over and believed to be heading for Washington DC, but it crashed into a field in Pennsylvania after the passengers and crew tried to regain control.