Who was Pat Tillman and what was his cause of death?

Remembering Pat Tillman, a professional NFL player who abandoned it all to enlist in the U.S Army (75th Ranger Regiment) after the 9/11 attacks happened. He died this day, 15 years ago. [

Brett Favre compares Colin Kaepernick to 'hero' Pat Tillman

Bush warned not to say Tillman died in ambush