James Harness Dead -- 'Gold Rush' Star Dies at 57

4:00 PM PDT: Harness' kids say James died a week ago, after suffering a stroke a week before. They say the funeral will be held in Oregon Saturday.

James Harness, star of Discovery's "Gold Rush," is dead.

Harness -- who lived in Oregon -- had serious medical issues, including back injuries from a car accident that crippled him with pain.

He also had a serious addiction problem with pain pills, which triggered problems on the show. We're told he wasn't showing up for work and became so unreliable he was fired during season 2.

We do not know the cause of death or where he was when he died.

Harness was divorced and had a son and a daughter. He was 57.

R.I.P.