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.
Pan American World Airways
On September 6, 1970, two men hijacked Pan Am Flight 93, a Boeing 747–121 (N752PA) en route from Amsterdam to New York, as part of the Dawson's Field hijackings. The flight diverted to Beirut International Airport to take on board seven other gang members for the next leg to Cairo International Airport, where the hijackers ordered the aircraft evacuated and destroyed it with explosives.