Mark Landon, the oldest of Michael Landon’s nine children, was found dead at his West Hollywood home on Sweetzer Avenue on Monday. Mark was 60 years old and even though the cause of death was not immediately clear, there was no sign of foul play.

Mark appeared in three movies including “Us” , which was written and directed by his father Michael back in 1991 before he died of cancer at the age 54. Mark was adopted after Michael married his mother Dodie Levy-Fraser in 1956.