In this May 30, 1968, file photo, Bobby Unser celebrates winning the 52nd running of the Indian …

In this May 30, 1968, file photo, Bobby Unser celebrates winning the 52nd running of the Indian ...

In this May 30, 1968, file photo, Bobby Unser celebrates winning the 52nd running of the Indianapolis 500 auto race at Indianapolis Motor Speedway in Indianapolis, Ind. Three-time Indianapolis 500 winner Bobby Unser has died. He died of natural causes at his home in Albuquerque, New Mexico, on Sunday, May 2, 2021. He was 87.(AP Photo/File)