Bettmann / Contributor/Getty ImagesBy RYAN BURROW, ABC News

(CHICAGO) — Gale Sayers, one of the greatest running backs in NFL history has died. He was 77.

Sayers’ son Guy Bullard confirmed complications of dementia and Alzheimer’s disease as the cause of death, according The New York Times.

Born in Wichita, Kansas, Sayers played football for the University of Kansas, where he was known as the “Kansas Comet.” He later racked up just under 5,000 rushing yards and 56 touchdowns in his storied seven-year career with the Chicago Bears.  

He was a five-time All-pro, four-time Pro Bowler and first ballot Hall of Famer.

Sayers is perhaps best known for his close relationship with teammate Brian Piccolo, who died of cancer in 1970 at the age of 26. The two were believed to be the first interracial roommates for a major professional sports franchise. Their story was documented in a made for TV movie Brian’s Song.

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