At around 9:30pm on September 11, 2001, George Tenet, director of the Central Intelligence Agency (CIA) told President George W. Bush and U.S. senior officials that the CIA's Counterterrorism Center had determined that Osama Bin Laden and al-Qaeda were responsible for the September 11 attacks. Two weeks after the terrorist attacks on September 11, 2001, the Federal Bureau of Investigation connected the hijackers to al-Qaeda, a militant Salafist Islamist multi-national organization. In a number of video, audio, interview and printed statements, senior members of al-Qaeda have also asserted responsibility for organizing the September 11 attacks. Identifying the hijackers The FBI investigation into the attacks, codenamed operation PENTTBOM, was able to identify the 19 hijackers within days, as they made little effort to conceal their names on flight, credit card, and other records. By checking flight manifests and comparing them with other information, like watch lists, customs officials were able to find the names of all 19 hijackers quickly. Passengers and crew aboard the flights provided information about the hijackers while the hijacking was in progress. Two flight attendants on American Airlines Flight 11, Betty Ong and Madeline Amy Sweeney, contacted airline personnel on the ground. Sweeney provided the seat numbers of the hijackers, and descriptions of the men, identifying Mohamed Atta as one of the hijackers. A flight attendant on United Airlines Flight 175 called a United Airlines mechanic and reported that hijackers had killed the crew. While the hijacking was in progress on American Airlines Flight 77, several passengers, including a flight attendant, Renee May, contacted and reported details of the hijacking to persons on the ground. Sales clerks identified two individuals to whom they sold tickets on Flight 77 as the hijackers Hani Hanjour and Majed Moqed. During the hijacking of United Airlines Flight 93, Jeremy Glick identified the hijackers as Arabic-looking and carrying box-cutters. Mohamed Atta's luggage did not make the connection from his Portland flight to American Airlines Flight 11. In his suitcase, authorities found a handwritten letter in Arabic. As well, a handwritten letter was found at the crash site of United Airlines Flight 93 near Shanksville, Pennsylvania, and another in Hazmi's vehicle. When examining Mohamed Atta's left-behind luggage, the FBI found important clues about the hijackers and their plans. Atta's luggage contained instructional videotapes for flying large aircraft, a fuel consumption calculator, and a flight plan, along with a copy of the Quran. His