Communication during the September 11 attacks

Communication problems and successes played an important role in the September 11, 2001 attacks and their aftermath.

Attackers
The organizers of the September 11, 2001 attacks apparently planned and coordinated their mission in face to face meetings and used little or no electronic communication. This "radio silence" made their plan more difficult to detect.

Federal government
According to 9/11 Commission staff statement No. 17 there were several communications failures at the federal government level during and after the 9/11 attacks. Perhaps the most serious occurred in an "Air Threat Conference Call" initiated by the National Military Command Center (NMCC) after two planes had crashed into the World Trade Center, but shortly before The Pentagon was hit. The participants were unable to include the Federal Aviation Administration (FAA) air traffic control command center, which had the most information about the hijackings, in the call.

According to the staff report: Operators worked feverishly to include the FAA in this teleconference, but they had equipment problems and difficulty finding secure phone numbers. NORAD asked three times before 10:03 to confirm the presence of FAA on the conference, to provide an update on hijackings. The FAA did not join the call until 10:17. The FAA representative who joined the call had no familiarity with or responsibility for a hijack situation, had no access to decision makers, and had none of the information available to senior FAA officials by that time.

We found no evidence that, at this critical time, during the morning of September 11, NORAD’s top commanders, in Florida or Cheyenne Mountain, ever coordinated with their counterparts at FAA headquarters to improve situational awareness and organize a common response. Lower-level officials improvised—the FAA’s Boston Center bypassing the chain of command to contact NEADS. But the highest level Defense Department officials relied on the NMCC’s Air Threat Conference, in which FAA did not meaningfully participate.

First responders
After the 1993 World Trade Center bombing, radio repeaters for New York City Fire Department communication were installed in the tower complex. Because they were unaware that several controls needed to be operated to fully activate the repeater system, fire chiefs at their command post in the lobby of the North Tower thought the repeater was not functioning and did not use it, though it did work and was used by some firefighters. When police officials concluded the twin towers were in danger of collapsing and ordered police to leave the complex, fire officials were not notified. Fire officials on the scene were not monitoring broadcast news reports and did not immediately understand what had happened when the first (South) tower did collapse.

There was little communication between New York City Police Department and fire department commands even though an Office of Emergency Management (OEM) had been created in 1996 in part to provide such coordination. A primary reason for OEM's inability to coordinate communications and information-sharing in the early hours of the WTC response was the loss of its emergency operations center, located on the twenty third floor of 7 World Trade Center which had been evacuated after debris from tower's collapse struck the building, igniting several fires.

Emergency relief efforts in both Lower Manhattan and at the Pentagon were augmented by volunteer amateur radio operators in the weeks after the attacks.

Victims
Cell phones and in-plane credit card phones played a major role during and after the attack, starting with hijacked passengers who called family or notified the authorities about what was happening. Passengers and crew who made calls include CeeCee Lyles, Sandra Bradshaw, Todd Beamer, Tom Burnett, Mark Bingham, Peter Hanson, Jeremy Glick, Barbara K. Olson, Renee May, Madeline Amy Sweeney, Betty Ong, Robert Fangman, Brian David Sweeney, and Ed Felt. Passengers aboard United Airlines Flight 93 were able to assess their situation based on these conversations and plan a counter attack that resulted in the aircraft crashing before it reached its intended target. According to the commission staff: "Their actions saved the lives of countless others, and may have saved either the U.S. Capitol or the White House from destruction"

After each of the hijacked aircraft struck the World Trade Center, people inside the towers made calls to family and loved ones; in many cases, this was the last time they were ever heard from. Other callers directed their pleas for help to 9-1-1. Over nine hours of the 9-1-1 calls were eventually released after petitioning by The New York Times and families of the WTC victims.

General public
After the attack, the cell phone network of New York City was rapidly overloaded as traffic doubled over normal levels. Cell phone traffic also overloaded across the East Coast leading to crashes of the cell phone network. Since three of the major broadcast networks had their transmission towers atop the North Tower (One World Trade Center), coverage was limited after the collapse of the tower. The satellite feed of one station, WPIX, froze on the last image received from the WTC mast; the image (a remote-camera shot of the burning towers), viewable across North America (as WPIX is available on cable TV in many areas), remained on the screen for much of the day until WPIX was able to set up alternate transmission facilities. It shows the WTC at the moment that power was cut off to the WPIX transmitter, prior to the towers' collapse.

During the September 11, 2001 attacks, WCBS-TV channel 2 And WXTV-TV channel 41 stayed on the air. Unlike most of the other major New York television stations, it had long maintained a full-powered backup transmitter at the Empire State Building after moving its main transmitter to the North Tower of the World Trade Center. The station was also simulcasted nationally on Viacom (which at the time owned CBS) cable network VH1 that day. In the immediate aftermath of the attacks, the station lent transmission time to the other stations who had lost their transmitters until they found suitable backup equipment and locations.

The Emergency Alert System was never activated in the terrorist attacks.

AT&T eliminated any costs for domestic calls originating from the New York City area (phones using area codes 212/718/917/646/347) in days following 9/11.