Counterterrorism “tsar” Richard Clarke learns of an aircraft heading toward the White House. Clarke, who is in the White House Situation Room, is passed a note by Secret Service Director Brian Stafford, which says, “Radar shows aircraft headed this way.” [Clarke, 2004, pp. 7] Around this time, the FAA’s Boston Center is reporting a low-flying aircraft six miles southeast of the White House (see 9:36 a.m. September 11, 2001), so this is presumably the same airliner to which Stafford’s note refers. [Vanity Fair, 8/1/2006] Clarke later comments that the Secret Service is aware of the approaching plane because it has “a system that allowed them to see what FAA’s radar was seeing.” [Clarke, 2004, pp. 7] Secret Service agent Barbara Riggs, who is in the agency’s Washington headquarters, will later corroborate this, recalling: “Through monitoring radar and activating an open line with the FAA, the Secret Service was able to receive real time information about… hijacked aircraft. We were tracking two hijacked aircraft as they approached Washington, DC, and our assumption was that the White House was a target.” [PCCW Newsletter, 3/2006] Stafford informs Clarke that he is going to evacuate the White House complex. (This evacuation appears to take place at around 9:45 (see (9:45 a.m.) September 11, 2001).) Those in the Situation Room are then informed that there has been an explosion at the Pentagon, and soon after that a plane has hit it. [Clarke, 2004, pp. 7]
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]
