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.
World Trade Center (1973–2001)
On September 11, 2001, Islamist terrorists hijacked American Airlines Flight 11 and crashed it into the northern façade of the North Tower at 8:46:40 a.m., the aircraft striking between the 93rd and 99th floors. Seventeen minutes later, at 9:03:11 a.m., a second group crashed the similarly hijacked United Airlines Flight 175 into the southern façade of the South Tower, striking it between the 77th and 85th floors. The damage caused to the North Tower by Flight 11 destroyed any means of escape from above the impact zone, trapping 1,344 people. Flight 175 had a much more off-centered impact compared to Flight 11, and a single stairwell was left intact; however, only a few people managed to pass through it successfully before the tower collapsed. Although the South Tower was struck lower than the North Tower, thus affecting more floors, a smaller number, fewer than 700, were killed instantly or trapped.