* Noll coached Steelers for 23 seasons from 1969
* Won Super Bowls in 1974, 1975, 1978 and 1979 seasons
Citing the Allegheny County Medical Examiner, media reported Noll died of natural causes at his home in Sewickley, Pennsylvania, in the presence of family members.
Noll, who was inducted into the Pro Football Hall of Fame in 1993, coached the Steelers for 23 seasons from 1969 until 1991, guiding the franchise to Super Bowl wins in the 1974, 1975, 1978 and 1979 seasons. Overall, he built a 209-156-1 record in all games, including a 16-8-0 post-season record, which is one of the best in league history.
In his first year at the helm the Steelers finished 1-13. Three years later, the Steelers reached the AFC championship game and two years after that they won their first Super Bowl.
"Through shrewd drafts and strong guidance, Noll helped team owner Art Rooney and the Steelers shed their 'lovable losers' image," according to a biography on the Pro Football Hall of Fame's website.
"He quickly established a building program with an emphasis on the annual college draft to realize the ultimate goal of an NFL championship."
This emphasis on the draft helped to build the fabled "Steel Curtain" defense and a powerful offense in the 1970s featuring defensive tackle "Mean Joe" Greene, quarterback Terry Bradshaw, and running back Franco Harris, among other Hall of Famers.
Noll graduated from the University of Dayton and went on to play seven seasons as a so-called messenger guard and a linebacker for the Cleveland Browns in the 1950s. He was an assistant coach for nine years before joining the Steelers.
Noll was a "tremendous technician in the individual fundamentals of football, which was something very important to him," Denver Broncos coach John Fox, who coached defensive backs under Noll for three seasons from 1989 through 1991, said in an interview published on the Steelers website in February.
"He was very calm, very technique and fundamental-oriented," Fox said. "He was not a screamer. He wasn't up or down. I think his biggest thing is that he was the same guy every day. He was not an ego guy like, 'Look what I'm doing.' He was a great mentor, I know that."