Todd Morgan Beamer (November 24, 1968 – September 11, 2001) was an American software salesman passenger aboard United Airlines Flight 93 which was hijacked as part of the September 11 attacks in 2001. He was one of the passengers who tried to reclaim the aircraft from the hijackers, leading them to crash it into a field in Stonycreek Township near Shanksville, Pennsylvania.

Source: http://en.wikipedia.org/wiki/Todd_Beamer