Donovan played in NFL for 12 seasons . He was elected to the Pro Football Hall of Fame in 1968 . Comment: The cause of Donovan 's death was not immediately disclosed .
Donovan played in NFL for 12 seasons . He was elected to the Pro Football Hall of Fame in 1968 . Donovan led the Baltimore Colts to world championships in 1958 and 1959 . The cause of Donovan 's death was not immediately disclosed .