Here's a look at the 9/11 Congressional Report, released by Congress on July 24, 2003.
The full name of the report is the Report of the Joint Inquiry into the Terrorist Attacks of September 11, 2001 by the House Permanent Select Committee on Intelligence and the Senate Select Committee on Intelligence.
Government and public administration
Government bodies and offices
International relations and national security
Osama Bin Laden
Terrorism and counter-terrorism
Unrest, conflicts and war
US federal government
US House of Representatives
Continents and regions
Government departments and authorities
Government organizations - US
The report is a result of a 10-month joint investigation by House and Senate intelligence committees. The report is completed in December 2002, but not published until July 2003 because of declassification.
The report is more than 800 pages, and there is a 20-page errata to the report available, which shows corrections made to the original. Twenty-eight pages that allegedly deal with Saudi Arabia's connections to the 19 hijackers remained classified until July 15, 2016.
Findings of the report:
FBI, CIA and other US intelligence agencies "missed opportunities" to thwart terrorism prior to September 11, 2001.
Although senior military officials were standing ready to strike al Qaeda terrorist Osama bin Laden prior to 9/11, they lacked the intelligence necessary for execution.
According to the report, "various threads and pieces of information" had either been overlooked or not put together.
"No one will ever know what might have happened had more connections been drawn between these disparate pieces of information," the report states. "The important point is that the intelligence community, for a variety of reasons, did not bring together and fully appreciate a range of information that could have greatly enhanced its chances of uncovering and preventing bin Laden's plan to attack the United States on September 11, 2001."
The report is the product of 5,000 interviews and a review of nearly one million documents.
The report includes some 19 recommendations to bolster counterterrorism efforts; those recommendations are originally released in 2002.
From "Abridged Findings and Conclusions":
Finding 1: "While the Intelligence Community had amassed a great deal of valuable intelligence regarding bin Laden and his terrorist activities, none of it identified the time, place, and specific nature of the attacks that were planned for September 11, 2001. Nonetheless, the Community did have information that was clearly relevant to the September 11 attacks, particularly when considered for its collective significance."
Finding 2: "During the spring and summer of 2001, the Intelligence Community experienced a significant increase in information indicating that bin Laden and al-Qaeda intended to strike against US interests in the very near future."
Finding 3: "Beginning in 1998 and continuing into the summer of 2001, the Intelligence Community received a modest, but relatively steady, stream of intelligence reporting that indicated the possibility of terrorist attacks within the United States. Nonetheless, testimony and interviews confirm that it was the general view of the Intelligence Community, in the spring and summer of 2001, that the threatened bin Laden attacks would most likely occur against US interests overseas, despite indications of plans and intentions to attack in the domestic United States."
Finding 4: "From at least 1994, and continuing into the summer of 2001, the Intelligence Community received information indicating that terrorists were contemplating, among other means of attack, the use of aircraft as weapons. This information did not stimulate any specific Intelligence Community assessment of, or collective US Government reaction to, this form of threat."
Finding 5: "Although relevant information that is significant in retrospect regarding the attacks was available to the Intelligence Community prior to September 11, 2001, the Community too often failed to focus on that information and consider and appreciate its collective significance in terms of a probable terrorist attack. Neither did the Intelligence Community demonstrate sufficient initiative in coming to grips with the new transnational threats. Some significant piece of information in the vast stream of data being collected were overlooked, some were not recognized as potentially significant at the time and therefore not disseminated, and some required additional action on the part of foreign governments before a direct connection to the hijackers could have been established. For all those reasons, the Intelligence Community failed to fully capitalize on available and potentially important information."
Findings from pages declassified July 15, 2016:
"While in the United States, some of the September 11 hijackers were in contact with, and received support or assistance from, individuals who may be connected to the Saudi Government. There is information, from FBI sources, that at least two of those individuals were alleged to be Saudi intelligence officers. The Joint Inquiry's review confirmed that the Intelligence Community also has information, much of which remains speculative and yet to be independently verified, indicating that Saudi Government officials in the United States may have other ties to al-Qaeda (al-Qa'ida) and other terrorist groups."