There was no single clue to tip off authorities what was planned for Sept. 11. But, a congressional report says important intelligence information wasn't shared.
One senator says what was needed was "skill, cooperation, creativity and some good luck.”
According to the report from congressional investigators, a chance to uncover the plot was lost when intelligence agencies failed to let the San Diego FBI office know that two men were suspected terrorists.
The two would later turn out to be among the hijackers.