A bizarre crash — even by auto racing standards — involving a spinning racecar and a track jet dryer during a caution period led to an explosion and a stream of jet fuel burning the asphalt entering Turn 3 of Daytona International Speedway.

“One thing about racing,” the driver Brad Keselowski said, “when you think you’ve seen it all, it finds a way to show you something you never thought you’d see.”

The Daytona 500 had not been raced on Monday until this year, when rain forced the first postponement of the race in its 54 years. Then the race was bumped to prime time when more rain delayed a noon start.

The race finally began Monday night and was down to its final 43 laps when the engine on David Stremme’s Toyota blew up and he spun out. The race was still under caution when Juan Pablo Montoya came off pit road after trying to find the cause of a vibration in his racecar. He was driving down the backstretch and about to enter Turn 3 when something broke in the car and he suddenly went sliding sideways down the track. He slid right into a truck carrying a jet dryer that was slowly driving along the outside wall of the track and blowing dust and dirt away. The truck carries as much as 200 gallons of jet fuel.

The crash with Montoya’s car burst the jet fuel tank and fuel streamed down the racetrack, catching fire. Flames burned all the way across the track, halting the race after 160 laps of 200. Nascar officials hoped to restart after a cleanup, but with more rain possibly on the way it was unclear what would happen. Dave Blaney led at the time of the stoppage.

Montoya, who left his burning car, was not harmed. The driver of the jet dryer truck was transported to a local hospital for evaluation but was not believed to be seriously injured.

“Every time I got on the gas I could feel the rear squeezing,” Montoya said. “When I was telling the spotter to have a look how the rear was moving the car just turned right.”

The race was immediately red flagged; drivers would have had to drive through the flames to get around the track. And in a sign of the times, Keselowski even sent a Twitter message while he was sitting in his car. Eventually, after Dale Earnhardt Jr. complained that he had to urinate, the drivers were allowed to get out of their racecars.

It was a stunning turn to a Speedweeks that had a bit of everything for Nascar, including the debut of Danica Patrick, the third woman to drive in the Daytona 500. It was not the coming out ball that Patrick would have wanted. With pack racing back at Daytona after rules changes eliminated the odd tandem-style drafting of a year ago, the big wrecks were back, too. And one happened on the second lap of the race, involving Patrick among others.

The part-time Cup driver Elliott Sadler tapped his No. 33 Chevrolet into five-time champion Jimmie Johnson’s No. 48 on the front stretch. That touched off a six-car wreck that collected Patrick; last year’s Daytona 500 champion, Trevor Bayne; the 2004 Cup champion, Kurt Busch in his new ride in the No. 51 with Phoenix Racing; and Clint Bowyer and David Ragan. Johnson took a serious hit from Ragan’s No. 34, which T-boned Johnson’s driver-side as his car sat in the middle of the track.

Patrick’s car sustained serious damage, and she was out of contention quickly. Patrick returned 12 laps down and lasted one lap; she then went back to the garage and did not get back on the track until she was 62 laps back of the field. It was a deflating debut for a driver who has garnered headlines all week.

“I can’t wait to see who was the bonehead who did that,” Ragan said.

The driver Kyle Busch added: “Are we all kidding ourselves? We just sat around for 36 hours, and we wreck on Lap 1.”

It was the third wreck in three races at Daytona for Patrick. She was bumped on the final lap of the qualifying race Thursday, crashing hard into the wall as her racecar was destroyed. She was bumped again in the lower-level Nationwide race on Saturday, finishing 38th.

Johnson was unable to return, finishing 42nd for his worst career Daytona 500.

“I’m just really, really bummed to start the season this way,” Johnson said. “For all the hard work that has gone into getting this Lowe’s Chevrolet ready for tonight, we didn’t get to complete two and a half miles of green-flag racing. So I’m pretty bummed.”

nytimes.com