PITTSBURGH – Chuck Noll, who built the “Steel Curtain” Pittsburgh Steelers of the 1970s into one of the most dominant teams in pro football history, becoming the only NFL coach to win four Super Bowl championships, died Friday night in Pittsburgh. He was 82. Noll died of natural causes, the Allegheny County medical examiner said. When Noll was named the Steelers’ head coach in 1969, they had never reached a league championship game since their founding in 1933 and they were coming off a 2-11-1 season. Noll had played at guard and linebacker on powerful Cleveland Browns teams of the 1950s, but he had never been a head coach. The Steelers won only one game in Noll’s first season….