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.
One World Trade Center
At 8:46 a.m. (EDT) on September 11, 2001, five hijackers affiliated with al-Qaeda crashed American Airlines Flight 11 into the northern facade of the North Tower between the 93rd and 99th floors. Seventeen minutes later, at 9:03 a.m. (EDT), a second group of terrorists crashed the hijacked United Airlines Flight 175 into the southern facade of the South Tower, striking between the 77th and 85th floors.