John Gilbert Getty, the grandson of oil tycoon J. Paul Getty, was found dead in a hotel room in San Antonio. The causes of death are still unknown. Six years ago, his brother Andrew was mysteriously killed. With the death of John Gilbert Getty, the saga of the Getty dynasty, once led by the richest man in the world, is enriched by another sad event. John was the grandson of billionaire oil magnate J. Paul Getty and heir to the estimated $5 billion family fortune.