Report of the 9/11 Commission

September 11, 2001
The day began with the 19 hijackers getting through a security checkpoint system that they had evidently analyzed and knew how to defeat. Their success rate in penetrating the system was 19 for 19.They took over the four flights, taking advantage of air crews and cockpits that were not prepared for the contingency of a suicide hijacking.

On 9/11, the defense of U.S. air space depended on close interaction between two federal agencies: the Federal Aviation Administration (FAA) and North American Aerospace Defense Command (NORAD). Existing protocols on 9/11 were unsuited in every respect for an attack in which hijacked planes were used as weapons.

What ensued was a hurried attempt to improvise a defense by civilians who had never handled a hijacked aircraft that attempted to disappear, and by a military unprepared for the transformation of commercial aircraft into weapons of mass destruction.

A shootdown authorization was not communicated to the NORAD air defense sector until 28 minutes after United 93 had crashed in Pennsylvania. Planes were scrambled, but ineffectively, as they did not know where to go or what targets they were to intercept. And once the shootdown order was given, it was not communicated to the pilots. In short, while leaders in Washington believed that the fighters circling above them had been instructed to "take out" hostile aircraft, the only orders actually conveyed to the pilots were to "ID type and tail."

Like the national defense, the emergency response on 9/11 was necessarily improvised.

In New York City, the Fire Department of New York, the New York Police Department, the Port Authority of New York and New Jersey, the building employees, and the occupants of the buildings did their best to cope with the effects of almost unimaginable events-unfolding furiously over 102 minutes. Casualties were nearly 100 percent at and above the impact zones and were very high among first responders who stayed in danger as they tried to save lives. Despite weaknesses in preparations for disaster, failure to achieve unified incident command, and inadequate communications among responding agencies, all but approximately one hundred of the thousands of civilians who worked below the impact zone escaped, often with help from the emergency responders.

At the Pentagon, while there were also problems of command and control, the emergency response was generally effective. The Incident Command System, a formalized management structure for emergency response in place in the National Capital Region, overcame the inherent complications of a response across local, state, and federal jurisdictions.