6Dennis Byrd
This 26-year-old defensive player for the New York Jets back in 1992 suffered a terrible injury that ended his career. During a play against the Washington Redskins, Byrd collided with his teammate while attempting to bring down the Redskins quarterback. His head went directly into the chest of his fellow player, and it resulted in a career-ending injury and temporary paralysis (he was able to walk again later in his life).
