J.V. Cain was a tight end for the St. Louis Cardinals in the 1970s. He had been the tight end for six years and was racking up great statistics for the team.
On July 22, 1979, Cain was taking part in the teams training camp in order to get ready for the new season. This day was also his 28th birthday.
During camp, he was running a normal pass route and suddenly took a few steps backward, huddled over, and collapsed.
Cain died from congenital heart failure. Though he didn't die during the NFL Season, he still died doing something he loved.