A number of teams were forced to cut Preseason Thunder at Daytona International Speedway short after a 12-car crash destroyed their cars in Friday afternoon's testing session.

The chain reaction-crash started when Dale Earnhardt Jr. attempted to push Marcos Ambrose to the front while drafting in a 19-car pack on the backstretch.

"I felt like Marcos was backing up to me in (Turns) 1 and 2 to get a run down the back and I was just going to give him a push down the back straightaway and see if he could get the lead," Earnhardt Jr. said. "I was trying to eventually get to the lead myself and we got off the back straightaway and I was pushing him along there and are cars sort of didn't match up really well and I got him hooked into the fence."

It was heartbreak for Ambrose, who had the fastest Ford in single-car runs in both sessions yesterday.

“I just feel bad for my Stanley and Richard Petty Motorsports team,” Ambrose said. “You know, it's just – I got junior pushing me. He’s just a great drafter, really can feel it well. I just got caught on the edge of the bumper there and just with the shaped noses and the tires, just spun me out. It was hardly even a bump. It was just enough at the wrong angle, wrong time and just went for a spin."

The end result sent a number of drivers to the garage with heavy damage that included Ambrose, Aric Almirola, Jamie McMurray, Jeff Gordon, Kasey Kahne, Carl Edwards, Brad Keselowski, Joey Logano and Regan Smith. Since teams are still constructing the sixth-generation Sprint Cup cars, all the teams - except the No. 99 of Edwards - don't have backup cars.

"It’s too bad," Kahne said. "We still had a day of testing to go. We were making gains and things. But still we had a good day and a half, myself and the 24 team. Hopefully, we will be ready to come back."

Earnhardt will be able to finish out the test as his Chevrolet escaped with minor damage.

"We’ll go back to single car runs," Earnhardt Jr. said. "I don't think anybody wants anymore drafting after that. So we’ll just go back to running single car runs. We’re probably going to be here til 5 o’clock tomorrow working on our cars. We’ve got to find a little more speed."