Complex sentence: The Adamson family lived there until the mid- 1980s when sadly Douglas Adamson died at the house he loved, it was then sold to Drue Heinz, the widow H. J. Heinz II.The house is no longer open to the public.
Split into simpler sentences: The Adamson family lived there until the mid- 1980s when Douglas Adamson died. The Castle was then sold to Drue Heinz, the widow of H. J. Heinz II.The house is no longer open to the public.