9:45 a.m. September 11, 2001: White House Evacuated after Secret Service Learns of Plane en Route to Washington

The White House is evacuated after the Secret Service receives what the Associated Press describes as a credible threat of a terrorist attack against it. [Associated Press, 2001 ; CNN, 9/11/2001; CNN, 9/12/2001] Minutes earlier, in the White House Situation Room, Secret Service Director Brian Stafford informed counterterrorism “tsar” Richard Clarke that an aircraft was heading in their direction, and said he was going to order the evacuation of the White House (see (9:37 a.m.) September 11, 2001). [Clarke, 2004, pp. 7] The Secret Service learned of this aircraft by monitoring radar and over an open line with the FAA (the “hijack net”), which enable them to receive real time information about the hijacked aircraft. The Secret Service, which has been using an air surveillance system called Tigerwall for some time (see (September 2000 and after)), tracks both American 77 and United 93 as they approach Washington and assumes the White House is a target. Secret Service agent Barbara Riggs will later say, “The Secret Service prepared to defend the facility,” although the precise nature of the preparations is unclear. [New York Times, 9/12/2001; MSNBC, 9/22/2001; Daily Telegraph, 12/16/2001; Washington Post, 1/27/2002; Associated Press, 8/21/2002; 9/11 Commission, 6/17/2004; PCCW Newsletter, 3/2006] A slow and orderly evacuation of the White House had in fact begun earlier on (see (9:20 a.m.) September 11, 2001). But now the Secret Service orders people to run so as to evacuate faster. [CNN, 9/11/2001; ABC News, 9/11/2002]