A former American Airlines ticket agent who checked-in two hijackers involved in the attacks on Sept. 11, 2001 has lived with that decision for two decades, riddling him with guilt for allowing them on the flight the crashed into the Pentagon.

A former American Airlines ticket agent who checked-in two hijackers involved in the attacks on Sept. 11, 2001 has lived with that decision for two decades, riddling him with guilt for allowing them on the flight the crashed into the Pentagon.