On September 11th, 2001, a great tragedy struck America. Terrorists high-jacked airplanes and flew them into the two towers of the World Trade Center. The towers, approximately 1700 feet tall, were built to withstand an airplane crash, but the burning fuel was not accounted for. At 8:46am, the first plane hit the North Tower at the 96th floor. The plane flew right into staircases and elevators in the core of the tower. This prevented people from escaping. …showed first 75 words of 305 total…

…showed last 75 words of 305 total…columns buckle. The top portion slumps toward the damaged corner and rotates slightly. Unable to hold the top portion's 110,000-ton weight, the tower crumples floor by floor. Structurally crippled to a greater degree than its twin, the south tower remained erect for 56 minutes before crumpling in 10 seconds. The towers hit the ground at approximately 120 miles per hour. There was nothing that engineers could have done to prevent this tragedy as it is not always expected.