Before Sept. 11

The terrorist attacks on New York and Washington shocked the world, but reports of clues given to the U.S. intelligence community before Sept. 11 indicate not everyone should have been surprised.
An Algerian hijacking is foiled in Marseille, France. The French government reveals the target was the Eiffel Tower and warns the next step for terrorists is to train as pilots. A Pentagon-commissioned report concludes that religious terrorists could hijack commercial airliners and crash them into the Pentagon or the White House.
Philippine authorities arrest Ramzi Yousef, mastermind of the 1993 World Trade Center bombing, and Abdul Hakim Murad. Murad admits a link to Osama bin Laden and tells of a plot to fly a plane into CIA headquarters in Langley, Va. He says Mideast pilots were training at U.S. flight schools in preparation for a plan to blow up U.S. planes over the Pacific. The FBI is alerted and interviews flight school attendees, but fails to produce evidence against the Middle Easterners.
U.S. officials involved in the Murad investigation focus mostly on the Pacific Ocean plot because it was considered developed and imminent. The plan to use a plane as a weapon is largely discounted.
Aug. 1998
U.S. intelligence learns that a "group of unidentified Arabs planned to fly an explosive-laden plane from a foreign country into the World Trade Center," according to a report released by congressional investigators Sept. 18, 2002. The information was passed on to the Federal Aviation Administration and FBI, which took little action on it. The group may now be linked to bin Laden, the report says.
March 1999
According to a newspaper report published in February 2004, German intelligence officials claim this is around the time they gave the CIA the first name and telephone number of hijacker Marwan al-Shehhi, asking U.S. officials to track him. Al-Shehhi was a member of the al Qaeda cell in Hamburg and a roommate of Mohammed Atta. The Germans say they never heard back from U.S. officials until after Sept. 11.
French intelligence places Zacarias Moussaoui on a watch list for links to the Armed Islamic Group, responsible for 1995 bombings in the Paris subway. Moussaoui, the first man indicted in the Sept. 11 attacks, was once thought to have been the 20th hijacker, but stronger suspects have now emerged. He is awaiting trial on conspiracy charges.
CIA headquarters (AP Photo)
A Library of Congress report concludes that 'suicide bombers' could 'crash-land' an aircraft into the Pentagon, the CIA or the White House.
Ahmed Ressam (AP Photo)
U.S. Customs arrest Algerian Ahmed Ressam as he tries to cross the Canadian border in a rental car packed with explosives. He's later convicted of plotting to blow up the Los Angeles airport on the eve of the millennium, and receives a 22-year sentence. Ressam cooperates for a time with investigators, telling them about the internal workings of terror camps in Afghanistan.
A Philippine investigation leads to Malaysia and an Indonesian cleric named Hambali, who has ties to al Qaeda and other terrorist groups. In January he meets with two future Sept. 11 hijackers, Nawaf Alhazmi and Khalid Almihdhar, in Kuala Lumpur. Surveillance data shared with U.S. authorities reveals an unidentified al Qaeda operative from the Middle East, who will later become wanted in connection with the October 2000 attack on the USS Cole.
Jan. -Sept. 2001
FAA issues several warning to the airline industry of likely imminent hijackings of airplanes inside the United States.
Feb. 2001
Moussaoui is granted a U.S. visa to train as a pilot in the United States.
May-July 2001
The National Security Agency reports at least 33 communications indicating a possible, imminent terrorist attack.
May 2001
Intelligence agencies obtain information that supporters of bin Laden are planning to infiltrate the United States through Canada to carry out an attack using explosives.

Meanwhile, The Defense Department acquires information indicating that seven people associated with bin Laden have departed various locations for Canada, Britain and the United States. It is shared with other intelligence agencies.
June 2001
Condoleeza Rice (AP Photo)
CIA Director George Tenet warns National Security adviser Condoleeza Rice that a significant al Qaeda attack in the near future is 'highly likely'.
July 2001
In a White House meeting, counter-terrorism officials warn FAA, FBI and INS that a major attack on the U.S. is coming soon. Non-essential travel of U.S. counter-terrorism staff is suspended.
July 2001
Agent Kenneth Williams, in Phoenix, Az., sends an electronic memo to FBI headquarters, warning of an unusual number of Middle Eastern men enrolling in U.S. flight schools. He speculates they may be connected to a bin Laden plot. The memo recommends that the FBI canvass other schools nationwide. Officials never follow up.
July 2001
Egyptian President Hosni Mubarak with Mr. Bush (AP Photo)
Italy closes Genoa's airspace during the G-8 summit after Egyptian President Hosni Mubarak passes information to Washington about a possible threat on President Bush's life, following a June 13 video made by bin Laden.
July 2001
French-Algerian Djamel Beghal is arrested in Dubai with a false passport. He details an al Qaeda plot to blow up U.S. interests in Europe, including the American Embassy in Paris. He says he met with bin Laden operatives at mosques in Britain, had weapons training in Afghanistan and met at bin Laden's home with his top aide, Abu Zubaydah.
July 2001
The CIA's counterterrorist center becomes aware of an individual who had recently been in Afghanistan who reported, "Everyone is talking about an impending attack."
Summer 2001
Israeli intelligence services, aware bin Laden is planning a large-scale terror attack, pass information along to Washington.
Aug. 2001
Almihdhar and Alhazmi (AP Photo)
CIA warns government agencies that Alhazmi and Almihdhar, who later crashed American Airlines 77 into the Pentagon, should be put on a terrorist watch list.
Aug. 2001
President Bush is briefed at his Crawford, Texas ranch, about possible attacks, including a warning that bin Laden may hijack planes. The administration quietly puts law enforcement, certain federal agencies and U.S. embassies on alert.
Aug. 2001
Moussaoui (AP Photo)
Moussaoui is arrested on a visa violation after telling his flight instructor in Minnesota that he wants to learn to fly a commercial plane, but not to take off or land. FBI Headquarters subsequently deny requests from the Ninneapolis FBI field office to search Moussaoui's computer.
Sept. 9, 2001
Suspected bin Laden operatives assassinate northern alliance leader Gen. Ahmed Shah Massood in Afghanistan. The killing was designed to weaken the northern alliance just days before attacks on the U.S. prompted a response against the Taliban.
Sept 10, 2001
European authorities begin looking into the plot against U.S. interests in Europe.
July 24, 2003
A 900-page report by the House and Senate intelligence committees concludes the CIA failed to act on intelligence it had about hijackers, the FBI was unable to track al Qaeda in the United States and key National Security Agency communications intercepts never were circulated. But no evidence is found to show that the government could have prevented the Sept. 11 attacks.