8:46 a.m. September 11, 2001: Power Briefly Goes Off in WTC 7 When the North Tower Is Hit

The electrical power in World Trade Center Building 7, a 47-story office building located north of the Twin Towers, goes off around the time Flight 11 crashes into the North Tower but it comes on again after a few seconds. [National Institute of Standards and Technology, 9/2005, pp. 109]
Lights Go Out When Flight 11 Crashes – Firefighter Timothy Brown, a supervisor at New York City’s Office of Emergency Management (OEM), which has offices in WTC 7, notices when the power goes off and immediately realizes something serious must have occurred. He is in the cafeteria on the third floor of WTC 7 eating his breakfast and does not feel any vibration or hear any explosion when Flight 11 hits the North Tower (see 8:46 a.m. September 11, 2001). However, he notices the lights in the cafeteria suddenly going out. After about three to five seconds, the power kicks back in and the lights come back on.
People by the Windows Report What Has Happened – It is “very unusual for lights to go out,” Brown will later comment. [City of New York, 1/15/2002; Project Rebirth, 6/30/2002 ; Firehouse, 1/31/2003] Because of his experience in “emergency stuff,” he knows immediately that “something big had just happened.” He is initially unaware of what it is but soon learns what has occurred. [Radio on the Real, 7/9/2013] The people in the cafeteria sitting by the windows facing the North Tower suddenly get up and start running, and when Brown asks them what is wrong, he is told a plane just crashed into the tower. [City of New York, 1/15/2002; Firehouse, 1/31/2003]
Elevator Stops When the Crash Occurs – Calvin Drayton, a deputy director with the OEM, also notices the loss of power. While he is going down in an elevator in WTC 7, he hears a noise that he thinks is a “transformer explosion.” The explosion “rocked the building and temporarily stopped the elevator,” he will recall. The elevator then continues down to the first floor and after Drayton gets off it he runs into a colleague who tells him there has been an explosion in the North Tower. [Greenville Tribune-Times, 9/25/2001]
Substation under WTC 7 Provides Power to the Complex – The reason the crash high up in the North Tower causes power to go off in WTC 7, which is located about 370 feet from the tower, is unclear. WTC 7 was built over an electrical substation owned by the utility company Con Edison and this substation now supplies power to the entire WTC complex. [National Institute of Standards and Technology, 11/2008, pp. 633] Before Flight 11 hit the North Tower, “all indications were that the power system was operating normally,” a report by the National Institute of Standards and Technology (NIST) will state. [National Institute of Standards and Technology, 11/2008, pp. 643]
Workers See No Damage in the Substation – Con Edison employees are at the substation around the time of the crash. These include two mechanics who are there to perform scheduled work and are at the site when the crash occurs or arrive shortly afterward. The Con Edison employees will be at the substation until around 10:20 a.m., when it is evacuated. They will notice “[n]o fire or significant physical damage” at the substation that could have caused the power to go out, according to NIST. [National Institute of Standards and Technology, 11/2008, pp. 357, 640]
Power Loss Is Reportedly due to ‘Collateral Damage’ Caused by the Crash – According to Con Edison, the loss of power occurs because two “open/auto” feeders go off. [9/11 Commission, 2/26/2004 ] (Feeders are sets of conductors that distribute power from a substation. [National Institute of Standards and Technology, 11/2008, pp. 637] ) According to NIST, “two of the circuits [i.e. the feeders] tripped automatically… as a result of collateral damage caused by the aircraft impact into [the North Tower].” [National Institute of Standards and Technology, 11/2008, pp. 643] The power comes back on quickly because “it was rerouted automatically by computers,” according to Brown. [Firehouse, 1/31/2003] “The backup system kicked in, another feeder kicked in,” he will explain. [Radio on the Real, 7/9/2013] The power in WTC 7 will go off again at around 9:03 a.m., when Flight 175 crashes into the South Tower (see 9:03 a.m. September 11, 2001). [9/11 Commission, 2/26/2004 ; National Institute of Standards and Technology, 11/2008, pp. 643]