On September 11, 2001, as part of a coordinated attack, members of al Qaeda, an Islamic extremist group, hijacked and crashed airplanes into the Twin Towers of the World Trade Center in New York City, the Pentagon in Washington D.C., and another being brought down in Pennsylvania before it could arrive at its intended target. Both World Trade Center towers collapsed, leading to the deaths of 2,753 people and hurting many thousand more - injuries some still live with today.