World Trade Center Health Program
On September 11, 2001, 19 terrorists associated with the Islamist militant group al-Qaeda hijacked four passenger jets in a series of suicide attacks on the United States, killing 2,996 people and injuring more than 6,000 others. Hijackers flew planes into two main towers of the World Trade Center, resulting in the collapse of three buildings of the World Trade Center complex, and the Pentagon, resulting in the partial destruction of the western side in the building. The resulting dust cloud due to the collapse of the World Trade Center covered Manhattan for days and contained thousands of tons of toxic debris, including asbestos and other known carcinogens. Another hijacked plane crashed into a field in Shanksville, Pennsylvania following an attempt by the passengers to retake control of the plane. No one in the airliners survived.
As of 2011, approximately 18,000 people have received medical treatment for illnesses related to toxic dust from the World Trade Center site. A study of rescue workers released in April 2010 found that all those studied had impaired lung functions, and that 30–40% were reporting little or no improvement in persistent symptoms that started within the first year of the attack. In 2011 a major research study showed significant long term medical and psychological effects among first responders to the World Trade Center site. These effects include elevated levels of asthma, sinusitis, Gastroesophageal reflux disease and posttraumatic stress disorder.
Mohamed Atta
The hijacking began at 8:14 am — 15 minutes after the flight departed — when beverage service would be starting. At this time, the pilots stopped responding to air traffic control, and the aircraft began deviating from the planned route. At 8:18 am, flight attendants Betty Ong and Madeline Amy Sweeney began making phone calls to American Airlines to report what was happening. Ong provided information about lack of communication with the cockpit, lack of access to the cockpit, and passenger injuries. At 8:24:38 am, a voice believed to be Atta's was heard by air traffic controllers, saying: "We have some planes. Just stay quiet and you will be OK. We are returning to the airport." "Nobody move, everything will be OK. If you try to make any moves you'll endanger yourself and the airplane. Just stay quiet." "Nobody move, please. We are going back to the airport. Don't try to make any stupid moves." The plane's transponder was turned off at 8:21 am. At 8:46:35 am, Atta flew the plane into the North Tower of the World Trade Center.