60-year-old Mark Landon, is the eldest son of legendary actor Michael Landon, was found dead in his West Hollywood home on Monday. He was found about noon in the 1300 block Sweetzer Avenue.

Michael Landon was an American actor, writer, director and producer who starred in three popular NBC TV series that spanned for decades. He is popularly known as Little Joe Cartwright in Bonanza, as Charles Ingalls in Little House on the Prairie and Jonathan Smith in Highway to Heaven. He died at 54 because of cancer.

Michael adopted Mark Landon after marrying his mother, Dodie Levy-Fraser, in 1956. Mark, among Michael’s nine children, appeared in three movies including a CBS television movie entitled “Us” which written and directed by his father in 1991 just before he died.

Although the cause of death was not immediately clear, according to the spokeswoman of Los Angeles County Sheriff’s Department who were conducting the investigation, there was no evidence of foul play.