Ron Palillo, 63, best known as the nerdy Arnold Horshack on the 1970s sitcom Welcome Back, Kotter, died Tuesday in Palm Beach Gardens, Fla., of an apparent heart attack.
Mr. Palillo was inextricably linked with the character he played from 1975 to 1979 on the ABC sitcom, in which the title character returns to his Brooklyn alma mater to teach. Horshack was the nasally teen who yelped, "Oooh, ooh," and shot his hand skyward whenever the teacher posed a question.
While the show was a ratings success and propelled John Travolta to stardom, it brought difficulty for Mr. Palillo.
He said he felt exiled throughout the 1980s, unable to find parts, sinking into depression, and rarely venturing from his apartment.