When the terrorist attacks began on September 11, 2001, numerous U.S. intelligence agencies and facilities that should have been closely following the catastrophic events taking place in the skies over America were unaware that anything was wrong. Because of their particular responsibilities and their advanced capabilities, agencies such as the FBI and the National Security Agency (NSA) should have been among the first to learn the details of the crisis. But, instead, they were apparently in an information blackout, and their knowledge of the attacks was limited to what they could learn from television reports.
The fact that key intelligence agencies and facilities experienced this problem, and all at the same time, suggests that the information blackout may have been intentional–an act of sabotage committed by the perpetrators of the attacks. Such an act could have been intended to render these agencies and facilities useless when their services were urgently needed, thereby helping to ensure that the attacks were successful.
MILITARY OFFICERS UNSUCCESSFULLY SOUGHT INFORMATION ABOUT THE ATTACKS
The lack of awareness of the crisis on September 11 is highlighted in the accounts of two military officers who contacted numerous facilities in their attempts to learn more about the attacks. These officers were Lieutenant Colonel Mark Stuart, an intelligence officer at NORAD’s Northeast Air Defense Sector (NEADS), and Major David McNulty, the senior intelligence officer of the 113th Wing of the District of Columbia Air National Guard at Andrews Air Force Base. 
Stuart and McNulty’s units had crucial roles to play on September 11. NEADS, based in Rome, New York, was responsible for coordinating the U.S. military’s response to the hijackings.  And “air defense around Washington, DC,” according to Knight Ridder, was provided “mainly by fighter planes from Andrews Air Force Base,” which is just 10 miles from the capital.  The DC Air National Guard was in fact known as the “Capital Guardians.”  It was therefore essential that Stuart and McNulty be provided with up-to-the-minute information on the attacks. That, however, did not happen.
NEADS was alerted to the first hijacking–that of American Airlines Flight 11–just before 8:38 a.m. on September 11, when an air traffic controller called to report the incident and request military assistance.  Beginning at around 8:48 a.m., Mark Stuart contacted several facilities to see if they had any information on the hijacking, beyond what he had already learned. These facilities included the FBI’s Strategic Information and Operations Center, the National Military Joint Intelligence Center, and the 1st Air Force headquarters. None of them could provide any additional information. A colleague of Stuart’s checked the SIPRNET–the U.S. military Internet system–for relevant information, but also without success. 
At Andrews Air Force Base, about five minutes or so after he learned that a second plane had hit the World Trade Center (the crash occurred at 9:03 a.m.), McNulty went to his “intel vault” and began seeking relevant information. He too checked the SIPRNET. He called agencies such as the FBI, the CIA, and the NSA. He also called units such as the Air Combat Command Intelligence Squadron and the 609th Air Intelligence Squadron. But he was unable to find out anything more than he had already learned from television reports. 
Other accounts provide further details of the lack of awareness of the catastrophic events within the military and other government agencies. Indeed, the information blackout appears to have been almost universal. One government official commented that the U.S. was “deaf, dumb, and blind” for much of September 11. 
AIR TRAFFIC CONTROLLERS NOTICED EARLY SIGNS OF THE CRISIS
Although many key facilities were unaware of what was happening at the time the WTC towers were hit, indications of the crisis had been evident much earlier on. These indications were received or noticed by the Federal Aviation Administration (FAA), which is responsible for operating the U.S. air traffic control system, or by American Airlines.
The first sign that something was wrong came nearly 33 minutes before Flight 11 crashed into the WTC, when communication with the plane was lost. Just before 8:14 a.m., the plane’s crew failed to respond to an instruction to climb to 35,000 feet. The air traffic controller at the FAA’s Boston Center who was handling Flight 11 tried repeatedly to contact the plane over the next 10 minutes, but without success. 
Boston Center controllers noticed a further indication of the emergency at 8:21 a.m., when Flight 11’s transponder–the equipment that transmits identifying information about a plane to radar screens–was turned off. This, according to the Christian Science Monitor, was “something more worrisome” than the loss of radio contact. 
Then, at around 8:25 a.m., the controller handling Flight 11 heard a couple of suspicious radio transmissions, apparently made by a hijacker on Flight 11, which led him to conclude that the plane had been hijacked. At that point, the Boston Center began notifying its chain of command within the FAA of the suspected hijacking. 
A minute later, at 8:26 a.m., Boston Center controllers noticed Flight 11 drastically changing course, turning sharply to the south.  This was a significant development. Darrel Smith, an intelligence officer working at FAA headquarters that morning, has commented that he was particularly alarmed when he learned about it, because such a deviation was like “changing directions off I-95 north and heading south.” Flight 11’s change of course “jeopardized the other flights in the surrounding airspace,” he said. 
AIRLINE RECEIVED EARLY NOTIFICATION OF THE EMERGENCY IN CALLS FROM FLIGHT ATTENDANTS
American Airlines, like the FAA, was aware of the crisis well before the first plane hit the WTC. At 8:19 a.m., Betty Ong, one of the flight attendants on Flight 11, contacted the American Airlines Southeastern Reservations Office in Cary, North Carolina, and, in a 25-minute phone call, relayed crucial information about what was happening on her plane. A couple of minutes after Ong’s call began, a supervisor at the reservations office called the American Airlines System Operations Control Center in Fort Worth, Texas, and alerted it to the information that Ong was providing. And at 8:32 a.m., Amy Sweeney, another of the plane’s flight attendants, reached the American Airlines flight services office in Boston. In a 12-minute phone call, she provided details of the crisis to the manager there.
In their calls, Ong and Sweeney made clear the seriousness of the situation. They reported that Flight 11 had been hijacked and that the hijackers were in the cockpit; two flight attendants had been stabbed; one passenger had his throat slashed and died as a result; and there was a bomb in the cockpit. 
But while American Airlines and the FAA knew details of the emergency early on, other agencies and facilities that should also have been closely following the crisis were unaware that anything was wrong. So when Mark Stuart, at NEADS, contacted a number of intelligence facilities, beginning shortly after the first plane hit the WTC, he found they had no information beyond what he already knew.  And David McNulty, at Andrews Air Force Base, has recalled that when he did the same, beginning several minutes after the second plane hit the WTC, he felt like he was “waking up the national agencies” and found that the agencies he called “had nothing to report.”