Daytona 500 pole winner Alex Bowman in 16-car pileup

The Big One hit only 15 laps into the Daytona 500 on Sunday, triggered when Aric Almirola turned into pole winner Alex Bowman and started a 16-car pileup.

Minutes later, the race was stopped by lightning, and fans who had been socially distanced in the grandstands instead had to seek shelter in the crowded concourse. Heavy rain followed, shutting down "The Great American Race'' for a lengthy delay.

The race resumed after nearly six hours with Michael McDowell avoiding another crash on the final lap to capture the victory.

Christopher Bell started the early race melee when he pushed Almirola too hard near the front of the field and forced the Stewart-Haas Racing driver to bobble as he tried to avoid a slide. Almirola ended up turning right into Bowman. Their contact caused others to collide, sending them spinning and skidding through grass and mud. Martin Truex Jr., Erik Jones, Jamie McMurray, Ryan Blaney, William Byron, Ryan Newman, Daniel Suarez and Kurt Busch were among those involved.

"We were just getting pushed too hard too early," Almirola said, according to NASCAR.com. "It's a long, long race. Man, we were in a fine position, just sitting there riding around in the top two, three and the 20 [Bell] just came with a big run and hit me really hard in a bad spot and it turned me to the right and tore up our race car and ended our Daytona 500 way too early."

Almirola, Bowman, Newman, Jones and Suarez are among those listed now as out for the race, according to NASCAR.com.

Hendrick Motorsports had put Bowman and Byron on the front row.

Newman was nearly killed in a horrific accident on the last lap of last year's Daytona 500. Newman walked away safely Sunday and even checked on Busch as he sat in his Chevy.

The Associated Press contributed to this report.