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.
United Airlines Flight 93
After the hijackers took control of the plane, several passengers and flight attendants learned from phone calls that suicide attacks had already been made by hijacked airliners on the World Trade Center in New York City and the Pentagon in Arlington County, Virginia. Many of the passengers then attempted to regain control of the aircraft from the hijackers. During the struggle, the plane crashed into a field near a reclaimed strip mine in Stonycreek Township, near Indian Lake and Shanksville, about southeast of Pittsburgh and northwest of Washington, D.C. A few people witnessed the impact from the ground, and news agencies began reporting the event within an hour.