Fans file out of the grandstand as a large thunderstorm approaches shortly after the start of the 2017 Brickyard 400, at the Indianapolis Motor Speedway on July 23, 2017 in Indianapolis, Indiana. The race has been red flagged till the storm passes. Photo by Edwin Locke/UPI

- Image ID: TXT7R3
Fans file out of the grandstand as a large thunderstorm approaches shortly after the start of the 2017 Brickyard 400, at the Indianapolis Motor Speedway on July 23, 2017 in Indianapolis, Indiana. The race has been red flagged till the storm passes. Photo by Edwin Locke/UPI
UPI / Alamy Stock Photo
Image ID: TXT7R3