At 8:46 a.m., American Airlines Flight 11 crashed with a speed of about 490 mph into the north side of the north tower of the World Trade Center between floors 94 and 98.
At 9:02 a.m., United Airlines Flight 175 crashed with a speed of about 590 mph into the south side of the south tower between floors 78 and 84.
At 9:37 a.m., American Airlines Flight 77 crashed into the west side of the Pentagon. The crash killed all 59 people on board and 125 Pentagon personnel.
At 10:03 a.m., United Airlines Flight 93 crashed in a field southeast of Pittsburgh in Somerset County, Pa., killing everyone on board.
DoD News Update: Obama, Carter Honor Victims of 9/11 Terrorist Attacks
Full Event: Obama, Defense Leaders Speak at 9/11 Observance Ceremony
In the 15 years since terrorists attacked the United States, the steadfast love and faithfulness of survivors, families and friends of those who died have been an inspiration to President Barack Obama and the entire country, the commander-in-chief said at the Pentagon 9/11 Memorial observance. Story
Even after 15 years, those who experienced the horror of the 9/11 terrorist attack on the Pentagon say they remember it as if it was yesterday. Story
Since 9/11, soldiers with the New York National Guard have signed on as part of Joint Task Force Empire Shield, which places a military presence at transit hubs throughout New York City to prevent another terrorist attack. Story
Troops Attend 9/11 Ceremony in Afghanistan