Ron Palillo aka Arnold Horshack, one of the Sweathogs on the classic sitcom Welcome Back Kotter, died this morning of an apparent heart attack at his home near Palm Beach, Florida. He was 63. His body was discovered by his longtime partner Joseph Gramm at around 4AM. According to TMZ, Palillo was a heavy smoker and had been suffering from a bad cough. Sadly, he had planned to see a doctor today.