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.
New York City Fire Department
On September 11, 2001, American Airlines Flight 11 and United Airlines Flight 175 were hijacked by Islamic terrorists affiliated with Al Qaeda and flown into the World Trade Center's North and South Towers, respectively, causing massive damage to both towers during impact, and starting fires that caused the weakened 110-story skyscrapers to collapse within less than two hours.