“Sleepaway Camp” star Jonathan Tiersten has died. He was 60. The actor passed away at his New Jersey home last week, his brother, William Tiersten, told TMZ on Tuesday. The cause of death is under investigation. “Sleepaway Camp” star Jonathan Tiersten (seen here) has died. Instagram/jonathantiersten The actor — who portrayed Ricky Thomas (seen here) — was 60. American Eagle Films Jonathan got his start in the entertainment industry in 1981 when he appeared in an episode of the TV drama “Another World.” His breakout role was as Ricky Thomas in the 1983 Robert Hiltzik-directed horror film, “Sleepaway Camp.” The horror film follows a series of murders that occur at a teenage summer camp. His brother, William, told TMZ that he was found dead in his New Jersey home. Seen here: Tiersten in overalls. Instagram/jonathantiersten Tiersten’s cause of death is under investigation. Seen here: The actor in a selfie.…