Vikings players say they're in shock today over the death of teammate Korey Stringer. Stringer died early this morning of heat stroke, a day after collapsing at the team's training camp in Mankato on the hottest day of the year. The offensive lineman was 27 years old. Irv Cross is a former NFL player, coach and CBS football commentator who is now athletic director at Macalaster College. Cross says pro players are extremely competitive and often push themselves too hard to prove they deserve their position on the team.