Elder Wirthlin had gone to bed at his Salt Lake City home, and died peacefully at about 11:30 pm of causes incident to age. His oldest daughter, Jane Wirthlin Parker, was present. A member of the family had been staying and caring for Elder Wirthlin, whose wife, Elisa Young Rogers Wirthlin, died in 2006.
He had continued to work at his office right up until the Thanksgiving holiday.
Funeral arrangements will be announced.