(Bobby Bank/Getty Images)

Earlier this year, Bobby Hegyes, who played Juan Epstein on "Welcome Back Kotter," passed away. Now, another member of the Sweathogs is gone.

The Palm Beach Post reports that Ron Palillo, who played Arnold Horshack on the show, has died. He was 63. Friends tell the paper that Palillo passed away at his home in Palm Beach Gardens, Florida Tuesday morning.

TMZ reports that Pallilo died of a heart attack. According to the site, he was found by his partner of many years, Joseph Gramm, early Tuesday morning. Gramm called an ambulance, and the actor was rushed to the hospital, where he was pronounced dead.

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Palillo's Horshack was one of the most memorable characters on "Welcome Back Kotter," thanks to his catchphrase "Ooh, ooh! Mr. Kotter!" and his distinctive, hyena-like laugh.

After "Kotter," Palillo had other supporting TV roles, provided the voice for some animated shows such as "Darkwing Duck," and in 1996, he played himself in a few episodes of the TV show "Ellen." He also created the artwork for two children's books, and appeared onstage in productions of Amadeus and Guys and Dolls. His first play, The Lost Boy, was produced in 2005.

In recent years, Palillo had been a teacher at the G-Star School of the Arts for Motion Pictures and Broadcasting.