Between 8:47 a.m. and 8:55 a.m. September 11, 2001: Deputy Fire Safety Director Orders Evacuation of WTC’s North Tower, but Announcement Is Unheard

Lloyd Thompson, the deputy fire safety director in the North Tower of the World Trade Center, attempts to make an announcement instructing workers to evacuate the building, but the public address system was damaged by Flight 11 hitting the tower and so no one hears it. Thompson works for OCS Security, which holds the security contract for the WTC, and is on duty at the fire command desk in the ground-floor lobby of the North Tower. There, he is responsible for watching the building’s various security and fire safety computer systems. [9/11 Commission, 5/18/2004 ; New York Times, 5/22/2004; Dwyer and Flynn, 2005, pp. 45]
Announcements Attempted, but Public Address System Is Damaged – After Flight 11 hits the North Tower (see 8:46 a.m. September 11, 2001), following protocol, Thompson initially tries issuing instructions to just the floors of the building that have generated “computerized alarms,” according to the 9/11 Commission Report. In an announcement, he advises workers on those floors “to descend to points of safety—at least two floors below the smoke or fire—and to wait there for further instructions.” He then tries ordering the full evacuation of the tower over the public address system. [9/11 Commission, 7/24/2004, pp. 286] However, Thompson’s attempts at issuing instructions to people in the building are unsuccessful. The 9/11 Commission will state, “[T]he public address system was damaged [by the impact of the plane] and no one apparently heard the announcement.” [9/11 Commission, 5/18/2004 ]
Time of Attempted Evacuation Order Unclear – It is unclear when Thompson first tries ordering the full evacuation of the North Tower. He will tell the 9/11 Commission that he does so “within about 10 minutes” of Flight 11 hitting the building, meaning before 8:56 a.m. The reason for the delay, according to the 9/11 Commission Report, is that, although he was “immediately aware that a major incident had occurred” after Flight 11 hit the tower, Thompson “did not know for approximately 10 minutes that a commercial jet had directly hit the building.” However, when he is contacted by the deputy fire safety director in the South Tower at 8:49 a.m., just three minutes after the crash, Thompson tells his colleague that there has been “a major explosion” at the WTC, which, he says, “might be an aircraft” (see 8:49 a.m. September 11, 2001). [9/11 Commission, 7/24/2004, pp. 286-287; Dwyer and Flynn, 2005, pp. 27] Furthermore, George Tabeek, the Port Authority’s security manager for the WTC, will later say that “he called in to his fire safety command”—presumably referring to the fire command desks in the Twin Towers—“right after the first plane struck” and gave instructions “to evacuate the North Tower” (see Shortly After 8:46 a.m. September 11, 2001). [New Jersey Star-Ledger, 9/6/2011] Additionally, according to the 9/11 Commission Report, when fire department chiefs arrive in the lobby of the North Tower, Michael Hurley, the Port Authority’s fire safety director, tells them “that the full building evacuation announcement had been made within one minute of the building being hit.”
Automated Announcement Tells Workers to Stay in Offices – Around the time that Thompson is attempting to instruct people to evacuate the North Tower, the deputy fire safety director in the South Tower makes an announcement over that building’s public address system, advising workers to stay in—or return to—their offices, rather than evacuate (see (8:50 a.m.) September 11, 2001). [9/11 Commission, 7/24/2004, pp. 286-288] According to some security officers, an automated announcement was activated when Flight 11 crashed, which similarly instructs workers in the North Tower to stay in their offices, although it is unclear how many people hear that announcement (see Shortly After 8:46 a.m. September 11, 2001). [Newsday, 9/10/2002]