On the morning of September 11, 2001, Mohamed Atta, the leader of the hijackers and pilot of American Airlines Flight 11, took control of the plane. A chilling air traffic control recording captured his voice as he mistakenly transmitted a message meant for the passengers over the radio. His command was cold and direct: "We have some planes. Just stay quiet and you will be okay. We are returning to the airport." Moments later, Atta deliberately crashed Flight 11 into the North Tower of the World