The 71st Indianapolis 500 was held at the Indianapolis Motor Speedway in Speedway, Indiana, on Sunday May 24, 1987. After dominating practice, qualifying, and most of the race, leader Mario Andretti slowed with mechanical problems with only 23 laps to go. Five laps later, Al Unser Sr. assumed the lead, and won his record-tying fourth Indianapolis 500 victory. During the month of May, an unusually high 25 crashes occurred during practice and qualifying, with one driver in particular, Jim Crawford, suffering serious leg injuries.