Former Clemson University running back C.J. Fuller has died at the age of 22, the school announced Wednesday.

Fuller’s cause of death wasn’t immediately known. Pickens County, S.C. coroner told The State that autopsy results would take six to eight weeks to be made available.

“Our thoughts, prayers and deepest sympathies are with C.J.’s family,” Clemson football head coach Dabo Swinney said in a statement. “I’ve known C.J. a long time and watched him grow up through the Easley rec leagues all the way through Easley High School. I’m proud of what he accomplished as a Clemson Tiger, most of all, his accomplishment of being a Clemson graduate. Our deepest condolences and the thoughts of our program are with his family this evening. May he rest in peace.”

Fuller was an integral part of Clemson’s run in college football over the last couple of seasons.

The running back helped Clemson to three straight ACC championships and College Football Playoff appearances from 2015 to 2017.

He was credited with making key plays in Clemson’s 2016 blowout win against Ohio State in the playoff semifinal and in the title game against Alabama, in which they won their second national championship.

Fuller started the 2017 season as Clemson’s starting running back, but lost that role over the course of the season, according to ESPN. He announced in February he was going to play at a different school as a graduate transfer.

His personal life was troubled. Fuller was accused of robbing someone at gunpoint after allegedly breaking into an apartment with two other people in Clemson in March.