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.
Al-Qaeda
The September 11 attacks on America by al-Qaeda, killed 2,977 people, including 2,507 civilians, 343 firefighters, 72 law enforcement officers, and 55 military personnel. Two commercial airliners were deliberately flown into the twin towers of the World Trade Center, a third into the Pentagon, and a fourth, originally intended to target either the United States Capitol or the White House, crashed in a field in Stonycreek Township near Shanksville, Pennsylvania. It was also the deadliest foreign attack on American soil since the Japanese attack on Pearl Harbor on December 7, 1941.