Lisa Marie Presley‘s son Benjamin Keough died at the age of 27 on Sunday, July 12.TMZ reports that Elvis Presley and Priscilla Presley‘s only grandson died in Calabasas, California, from a self-inflicted gunshot wound.Keough, whose sister is actress Riley Keough, was an actor and musician who scored a five-album record deal with Universal worth $5 million in 2009.