Eighteen years ago today, nearly 3,000 people were killed in the Al-Qaeda terrorist attacks on Sept. 11, 2001. Islamic militants hijacked four airplanes fulfilling a long prepared attack on the United States in three different locations.
The first plane was a Boeing 767-200ER American Airlines Flight 11 which departed from Boston at 7:59 A.M. Under an hour later, the aircraft carrying 81 passengers flew into the North Tower of the World Trade Center at 440 mph.
The second plane was also a Boeing 767-200ER, United Flight 175. With 56 passengers aboard, the plane crashed into the South Tower at 9:03 A.M. at 540 mph.
American Airlines Flight 77, a Boeing 757-200, was the third plane that departed from Washington D.C. at 8:20 A.M. It crashed into the Pentagon at 530 mph around 9:37 A.M. with 58 passengers.
United Airlines Flight 93 was the same model as the third plane, a Boeing 757-200. It crashed into an empty field in Shanksville, Pennsylvania, flying 560 mph at 10:03 a.m.
As Americans remember the tragedy of that day almost two decades ago, here is a look at the day in photos.