Communication during the September 11 attacks

Communication problems and successes played an important role during the September 11 attacks in 2001 and their aftermath. Systems were variously destroyed or overwhelmed by loads greater than they were designed to carry, or failed to operate as intended or desired.

The organizers of the September 11, 2001 terrorist 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.

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 Complex, 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.

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 collapsed.

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. ^{[citation needed]} 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 the main tower's collapse struck the building. This ignited several fires that caused it to collapse at 5 pm later that day.^{[citation needed]}

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