Here's a look at what you need to know about the 9/11 Commission, whose report was released on July 22, 2004.
The Commission was created to provide a "complete account of the circumstances surrounding the September 11, 2001 terrorist attacks."
The official name of the 9/11 Commission is the National Commission on Terrorist Attacks Upon the United States.
The 570-page, 14-chapter report concluded that a "failure of imagination" kept U.S. officials from understanding the al-Qaida threat before the attacks on New York and Washington.
The report included 41 recommendations for reforming U.S. security agencies to fight terrorism.
The report calls for a single national intelligence chief and a single counterterrorism center modeled on the military's unified commands. It also proposes the creation of a single, joint congressional committee to oversee homeland security.
The purpose of the commission is to investigate U.S. counterterrorism policy from August 1998 to Sept. 11, 2001.
Budget for the commission totaled $15 million.
It originally has 18 months to report, or no later than May 27, 2004, but Congress and the president extend the reporting deadline by two months, to July 26, 2004.
The commission has nearly 80 full-time employees, contractors and employees on staff.
President George W. Bush and Vice President Dick Cheney agree to meet with commission chair and vice chair only.
Commission says it has had access to all documents and interviews it has requested.
"We've gotten everything we've asked for, but always after a lot of resistance and criticism," said member Slade Gorton.
It issues three subpoenas for information, but these are resolved without litigation. The subpoenas went to the Federal Aviation Administration (FAA), the Department of Defense, and the City of New York.
The commission reviewed more than 2 million pages of documents.
The commission's 10 Members:
Thomas H. Kean, chair - former governor of New Jersey (1982-1990).
Lee H. Hamilton, vice chair - former congressman
Richard Ben-Veniste - lawyer and former chief of the Watergate Task Force of the Watergate Special Prosecutor's Office.
Fred F. Fielding - Has served on several commissions, including Commission on Federal Ethics Law Reform (1989).
Jamie S. Gorelick - Serves on the CIA's National Security Advisory Panel.
Slade Gorton - Senator from Washington State from 1981-1987 and 1989-2001.
Bob Kerrey - Senator for Nebraska from 1988-2000 and Nebraska governor from 1983-1987.
John F. Lehman - Chairman of J.F. Lehman & Company, a private equity investment firm and former secretary of the Navy from 1981-1987.