Hall of Famer John Mackey, who helped revolutionize the position of tight end as an offensive weapon, died on Wednesday. He was 69 and had suffered from dementia for years. Mackey played 10 seasons for the Colts and Chargers, catching 331 passes for 5,236 yards and 38 touchdowns. As president of the NFL Players Association after the AFL-NFL merger, he fought to improve players' pension benefits and access to free agency. Enshrined in 1992, Mackey was the second player elected to the Hall of Fame as a tight end. He played in five Pro Bowls and was named All-NFL at his position three times.