We are saddened to report another star of the 70's series Welcome Back, Kotter has died. Dan Alexander of Townsquare Media reports, "Ron Palillo, best known as Arnold Horshack from the 70s sitcom Welcome Back, Kotter has died at age 63.

The Hollywood Reporter reports the actor died at his home in Palm Beach, Florida. but the cause of death is unknown. Friend Stacy Sacco says Palillo had not been ill and had been teaching at the G-Star School Of The Arts in Palm Springs, California.

He is the second Sweathog to pass this year; Robert Hegyes, who played Juan Epstein, died of a heart attack earlier this year.

Following his time on Kotter,Palillo struggled to expand beyond his role as Horshack.

Of Horshack, Palillo once told an interviewer from the Birmingham News: “While I loved him, I really loved him, I didn’t want to do him forever.”

He lent his voice to the animated Darkwing Duck & Laverne & Shirley In The Army and the soap opera One Life To Live among his many guest roles. He also appeared in many stage performances and wrote 2 children’s books, The Red Wings of Christmas and A Gift for the Contessa as Ronald G. Palillo. He used the more formal name in memory of his father.

He was defeated by Dustin Diamond, who played Screech on Saved by the Bell, in Fox’s Celebrity Boxing 2 in 2002