U.S. government officials suspect bin Laden was the culprit behind parallel attacks in Washington, D.C., and New York, where the World Trade Center collapsed into rubble with a loss of more than 3,000 lives after two hijacked commercial jetliners slammed into the twin buildings. The Pentagon also took a direct, devastating hit from a hijacked aircraft, killing more than 180 people. In the Sept. 11, 2001, coordinated hijacking of four commercial jetliners and attacks, 266 passengers were killed in addition to the thousands in New York and at the Pentagon.
Bin Laden also has been linked to Ramzi Ahmed Yousef, the mastermind of the 1993 World Trade Center bombing and is associated with Egyptian Sheik Omar Abdel-Rahman's Millenium New Year celebration plot to blow up tunnels and bridges around New York City and the Los Angeles airport.
Intensive investigations since the Sept. 11 attacks have uncovered what may been collection of al-Qaida affiliated operatives living and plotting in the United States.