Updated

An early wreck in the Daytona 500 has knocked out several top contenders, including three-time NASCAR champion Tony Stewart and 2007 race winner Kevin Harvick.

Stewart, winless in 14 starts in The Great American Race, says he is "heartbroken and disappointed."

The nine-car wreck started when Kasey Kahne let off the gas to slow as they neared the first turn at Daytona International Speedway. Kyle Busch tried to do the same, but couldn't avoid contact.

Busch sent Kahne spinning across the track. Juan Pablo Montoya, 2010 race winner Jamie McMurray and defending series champion Brad Keselowski also were involved. So were Kurt Busch and Casey Mears.

The accident ended Harvick's attempt to become the first in NASCAR history to win the exhibition Sprint Unlimited, a twin qualifying race and the Daytona 500 in the same Speedweeks.