Donald Rumsfeld
The United States was attacked on September 11, 2001 by al Qaeda terrorists who hijacked commercial airliners and crashed them in coordinated strikes into both towers of the World Trade Center in Lower Manhattan, New York City and the Pentagon in Washington, D.C. The fourth plane crashed into a field in Shanksville, Pennsylvania, and its target was likely a prominent building in Washington, D.C., most probably either the Capitol Building or the White House. Within three hours of the start of the first hijacking and two hours after American Airlines Flight 11 struck the World Trade Center, Rumsfeld raised the defense condition signaling of the United States offensive readiness to DEFCON 3, the highest it had been since the Arab-Israeli war in 1973.
American Airlines Flight 11
The 9/11 Commission estimated that the hijacking began at 08:14, when the pilots stopped responding to requests from the Boston Air Route Traffic Control Center (Boston ARTCC). It is believed that Waleed al-Shehri made the first move. At 08:13:29, as the aircraft was passing over central Massachusetts at , the pilots responded to a request from Boston ARTCC to make a 20-degree turn to the right. At 08:13:47, Boston ARTCC told the pilots to ascend to a cruising altitude of but received no response. It is believed that Captain Ogonowski was stabbed to death in order for the hijacker pilot Mohamed Atta to take control of the plane and crash it into the North Tower of the World Trade Center. Before dying, Ogonowski keyed the cockpit microphone; "pushing its button intermittently to signal that something was wrong and at one point allowing them to hear the voice of the hijacker." At 08:16, the aircraft leveled off at and shortly thereafter deviated from its scheduled path. Boston ARTCC made multiple attempts to talk to Flight 11 without reply, and at 08:21, the flight stopped transmitting its Mode-C transponder signal.