FBI agents, fire fighters, rescue workers and engineers work at the Pentagon crash site on Sept. 14, 2001, where a hijacked American Airlines flight slammed into the building on Sept. 11. The terrorist attack caused extensive damage to the west face of the building and followed similar attacks on the twin towers of the World Trade Center in New York City.

Pentagon, Arlington, Virginia, 2001

At about 9:40 a.m. on September 11, 2001, a hijacked airliner crashed into the western side of the Pentagon, killing 125 people on the ground, as well as 64 people on board the plane. Area hospitals treated 88 injured people. The crash damaged or destroyed three of the five interior concentric "rings" of the Pentagon building. The section where the plane hit had been recently renovated, and many offices were empty or being used for storage at the time.

Local responders arrived immediately, and other agencies, including five USAR teams, came to assist. The Arlington County Fire Department set up an incident command system and coordinated the emergency response. The rescue and recovery phase lasted 11 days, after which Arlington County transferred responsibility for the incident and site management to the Federal Bureau of Investigation (FBI), on September 21. No responders were killed.