DAYTONA BEACH -- Jamie McMurray had no idea what caused his car to wiggle, wobble and weave at nearly 200 mph Saturday night.

Whatever the reason, it triggered "The Big One" and wrecked more than half the field at Daytona International Speedway.

Nearly two dozen cars, including all four Hendrick Motorsports entries, were involved in the massive wreck a little past the halfway point of NASCAR's 400-mile race at Daytona.

Brad Keselowski won the race, kicking off the famed track's annual fireworks show at Daytona, but there were plenty of sparks and smoke on Lap 90.

All the chaos, confusion and crumpled cars began when McMurray got loose in Turn 1. He moved hard left for some reason, banged into Kyle Larson and then spun in front of much of the field after getting tapped from behind by Jimmie Johnson.

"I think somebody might have gotten into my left rear," McMurray said. "I don't know if that cut the tire down or what, but after I felt that happen, I just didn't have any control any more. It seemed like a tire maybe went down and it actually felt like I hit oil.

"It is unfortunate, but it is just part of plate racing."

The crash included Hendrick teammates Dale Earnhardt Jr., Jimmie Johnson, Kasey Kahne and Chase Elliott as well as Kevin Harvick, Danica Patrick, Kyle Larson, Matt Kenseth, Martin Truex Jr. and pole-sitter Greg Biffle.

"Just a bunch of cars crashing," Kenseth said. "Pretty much that was it."

It was a typical result at NASCAR's high-banked superspeedways, where cars run in close packs and major mistakes are magnified, but not many crashes involve nearly two dozen cars.

At Talladega in May, 35 cars were involved in at least one accident. Two cars got airborne, and The Associated Press estimated more than $10 million in damage during the race.

Last year's July race at Daytona ended with a horrific last-lap accident. Austin Dillon's car sailed upside down into the fence then shot back onto the track. The car was on its roof and mangled when it was hit hard by Keselowski.

The car tore down a section of fencing, debris scattered into the grandstands and crew members from several teams raced to check on Dillon. He walked away uninjured.

Most of the cars stayed on the ground in Saturday night's crash, although Brian Scott's rear wheels lifted off the ground as Harvick's nose slid underneath him.

"I didn't see a lot," Scott said. "We were in the wall and jacked up and I guess (Harvick) came up under me and drove underneath my car and then I was up in the air. It was a pinball effect. It is an unfortunate end. You always seem to get those big ones here in the Fourth of July race. Sometimes there is nothing you can do. There was no chance to ever miss that for our (car).

"It is just a product of this type of racing. When you are in the pack and there is one wreck ... there is no way for people to escape."