A Comprehensive Guide To 9/11

While America Slept: The True Story of 9/11 - ABC News:

...While the nation drifted through the dog days, however, a group of terrorists was in the final stages of planning a series of attacks that would kill 3,000 people on September 11. Much of the federal government seemed to have been in a summer daze as well, missing the warning signs of what would become the deadliest act of terrorism on U.S. soil. While some in the intelligence community raised red flags, the White House had brushed off warnings of an impending attack and the CIA was failing to share information with the FBI about the terrorists' travels...