The start of the Indianapolis 500 is expected to be delayed as a strong storm pushed into the area, forcing Indianapolis Motor Speedway officials to evacuate about 125,000 fans who had already arrived for “The Greatest Spectacle in Racing.”

The video boards inside the speedway flashed that a severe thunderstorm warning was in effect as the storm approached from the west. It was expected to bring heavy rain along with dangerous wind and lightning.

The brunt of the storm was expected to hit about 12:45 p.m. ET, right when the race was due to begin. There was no word on how long the delay would last, but speedway president J. Douglas Boles said officials are hoping a window after the initial band of rain would allow enough time to dry the track and complete at least 101 laps, making the race official.

The track takes about 90 minutes to dry, depending on a number of factors. Indianapolis Motor Speedway brought in NASCAR’s track drying equipment to use along with its own in the hopes of speeding up the process.

If the rain persists, or the window to run the race does not last long enough, the entire 200-lap race will be run Monday.

“No matter what decision we make at this point, it’s going to be a difficult one for some of our fans,” Boles said. “Our hope still, based on what the weather looks like, we can begin drying the track around 2:30 or 3:00 and be able to start.”

Also in question was Kyle Larson‘s plans to run the Indy 500 and Coca-Cola 600 in Charlotte on Sunday night.

The NASCAR star is attempting to become the fifth driver in history to complete “The Double” by running both races in the same day. The last to do it was Kurt Busch in 2014, and the only driver to complete all 1,100 miles was Tony Stewart in 2001.

Larson qualified fifth for his debut Indy 500 in a joint effort between Arrow McLaren and Hendrick Motorsports.

“I think our plan is to keep this as a priority,” Larson, who would need a waiver from NASCAR to miss the Cup Series race at Charlotte, said shortly before the grandstands were emptied. “I think I would be here racing.”

The defending winner of the Indy 500 is Josef Newgarden, whose Team Penske teammates Will Power and pole sitter Scott McLaughlin join him on the front row. McLaughlin broke the four-lap qualifying record with an average of 234.220 mph.

Newgarden has been trying to rebuild his reputation in the paddock after IndyCar discovered illegal push-to-pass software on the three Team Penske cars and threw out both Newgarden’s win and McLaughlin’s third-place finish in the season opener. President Tim Cindric, Newgarden’s strategist, is one of several team employees suspended for the race.

Only five drivers in 107 runnings have won “The Greatest Spectacle in Racing” in consecutive years.

Chevrolet clearly had the speed advantage in qualifying when the engine maker claimed the first eight spots on the grid. But Honda showed it can hold its own in race trim, which means there was no obvious favorite when the green flag drops.

Reporting by The Associated Press.