John Walton, the billionaire son of Wal-Mart founder Sam Walton, was killed in a small plane crash at the Jackson Hole airport in Wyoming.
Walton had been piloting a one-man ultra-light, experimental aircraft. According to a spokesperson for the National Park Service in Jackson Hole, the 58-year-old crashed shortly after takeoff around 1:20 p.m. local time.
The cause of the accident was not immediately known.
Walton acted as director for the more than 5,000 Wal-Mart stores around the world and was named to the Forbes 2005 list of the richest people in the world with a net worth of more than $18 billion.
Because the aircraft Walton was flying is considered "experimental," neither the NTSB nor FAA will investigate, leaving the investigation to be conducted by the Jackson Hole National Park Service.
Last year, Fortune magazine noted that the Wal-Mart family had given millions to the Children's Scholarship Fund, an organization co-founded by John Walton, which had provided education money for more than 62,000 children.
Walton also served as a medic in the Army during the Vietnam war and was awarded the Silver Star.
He leaves behind a wife and one child.