Franco Harris, the Hall of Fame running back whose heads-up thinking authored the “Immaculate Reception,” considered the most iconic play in NFL history, has died. He was 72.

Harris’ son, Dok, told The Associated Press his father died overnight. No cause of death was given.

His death comes two days before the 50th anniversary of the play that provided the jolt that helped transform the Steelers from also-rans into NFL elite and three days before Pittsburgh is scheduled to retire his No. 32 during a ceremony at halftime of its game against the Las Vegas Raiders.

Harris ran for 12,120 yards and won four Super Bowl rings with the Pittsburgh Steelers in the 1970s, a dynasty that began in earnest when Harris decided to keep running during a last-second heave by Steelers quarterback Terry Bradshaw in a playoff game against Oakland in 1972.

Harris, the 6-foot-2, 230-pound workhorse from Penn State, found himself in the center of it all. He churned for a then-record 158 yards rushing and a touchdown in Pittsburgh’s 16-6 victory over Minnesota in Super Bowl IX on his way to winning the game’s Most Valuable Player award. He scored at least once in three of the four Super Bowls he played in, and his 354 career yards rushing on the NFL’s biggest stage remains a record nearly four decades after his retirement.

Born in Fort Dix, New Jersey, on March 7, 1950, Harris played collegiately at Penn State, where his primary job was to open holes for backfieldmate Lydell Mitchell. The Steelers, in the final stages of a rebuild led by Hall of Fame coach Chuck Noll, saw enough in Harris to make him the 13th overall pick in the 1972 draft.