WASHINGTON (Sept. 11, 2008) One hundred eighty-four joint service troops stand unveil the Pentagon Memorial in Washington. The national memorial is the first to be dedicated to those killed at the Pentagon Sept. 11, 2001. The site contains 184 inscribed memorial units honoring the 59 people aboard American Airlines Flight 77 and the 125 in the building who lost their lives that day. U.S. Navy photo by Mass Communication Specialist 2nd Class Molly A. Burgess
The third plane came in low over the Arlington National Cemetery and struck the western face of the Pentagon, penetrating through three of the building's five rings. All 64 people on the plane, including the five hijackers, were killed; 125 in the Pentagon also died.
Attack on the Pentagon Still from video by CNN via Getty Images A video still shows American Airlines Flight 77 slamming into the western side of the Pentagon in Arlington, Virginia, at 9:37 a.m. ET on 9/11, claiming the lives of 59 persons on board. In addition, 125 military and civilian employees at work inside the Pentagon were killed by the crash.