The 1991 U.S. Open was the 91st U.S. Open, held June 13–17 at Hazeltine National Golf Club in Chaska, Minnesota, a suburb southwest of Minneapolis. Payne Stewart defeated 1987 champion Scott Simpson in an 18-hole Monday playoff to win the first of his two U.S. Open titles. It was the second of Stewart's three major championships. Play was interrupted during the first round due to a severe thunderstorm. Six people were struck by lightning while seeking shelter near the 11th tee, and one person was killed.