BENTONVILLE, Ark., June 27 /PRNewswire-FirstCall/ -- It is with great sorrow that Wal-Mart Stores, Inc., announces the death of John Walton. A Vietnam War hero, member of the Wal-Mart Board of Directors and philanthropist, Walton was killed when the ultra-light aircraft he was piloting crashed shortly after take-off from the Jackson Hole Airport in Grand Teton National Park. The crash occurred at approximately 1:20 p.m. CDT and the cause has not yet been determined. Walton, 58, was the aircraft's sole occupant. Walton was the second son of Wal-Mart founder, Sam Walton. As a board member of the Walton Family Foundation,...