Veteran journalist William Nack passed away Friday at the age of 77.

Nack was perhaps best known for his chronicles of the life and death of the greatest racehorse in history, Secretariat. 

Nack joined Sports Illustrated in 1978. He mainly covered horse racing, but worked on a variety of subjects including chess master Bobby Fischer, racing legend A.J. Foyt and and the horse racing cortisone scandal in the 1990s. He also wrote about Jackie Robinson’s breakthrough in May 1947 and the war of words between Muhammad Ali and Joe Frazier.

His 1990 story, “Pure Heart” was chosen as one of SI’s 60 most iconic stories. He talked about the piece in a 2015 interview with Ted Keith.”​

"It was a very truthful rendition of what happened," Nack said of the story's ending. "I can still remember leaning against that hotel room wall and sobbing. That horse had meant a lot to me and my family."

He wrote three books throughout his career, including one on Secretariat in 1975.

In 2001, Nack left Sports Illustrated and freelanced for numerous publications, including ESPN and GQ. Nack served as an advisor to the 2010 Disney movie Secretariat

Nack was born in Chicago in 1941 and then moved with his family to Skokie, Illinois at the age of 10. After graduating from the University of Illinois in 1966, he enlisted in the army. After serving, he moved out to New York and worked with Newsday, covering sports, politics and the environment for 11 years before joining SI. 

He won many awards throughout his career, including the ESPN Lifetime Achievement Award for Literary Sportswriting in 2017.