The most successful American football coach of all time, Chuck Noll, has died at the age of 82.Noll led the Pittsburgh Steelers to four Superbowl victories between 1975 and 1980.
Local media reported that he died of natural causes at his home in Sewickley, Pennsylvania.
He had a reputation as a meticulous coach and his team achieved renown for their defence - or the "Steel Curtain" as it became known.
"He will go down as the guy who helped create the mystique that exists now with the Steelers," Noll's successor as coach Bill Cowher told the Pittsburgh Post-Gazette.
A former linebacker with the team, Andy Russell, told the paper: "He'd tell us life is a journey and you never arrive. He was always telling us at some point to find our life's pursuit.
"I love the guy. He was a tremendous mentor in my life."