United Flight 93 was the final hijacked plane on September 11, 2001. It was the only jetliner not to make its intended target, the U.S. Capitol Building. Passengers and crew on the flight, who learned of the other hijackings, attempted to rush the cockpit and retake control from the terrorists. Instead, it crashed in a field in rural Pennsylvania, killing everyone on board. Their heroism will be remembered Saturday at a memorial in Shanksville, Pennsylvania. Nikole Killion reports.
