Cpl. Pat Tillman, USA

In 2002, Pat Tillman left a successful football career with the Arizona Cardinals to join the U.S. Army. He was killed in Afghanistan in 2004. The official story was that he was shot by enemy forces during an ambush, but it was later revealed that he may have been killed by friendly fire, and that Army commanders and members of the Bush administration covered up the truth of what had happened.

 

SOURCE: http://www.biography.com/people/pat-tillman-197041#mysterious-death