Dale Earnhardt twice fell asleep at the wheel of his car moments before he drove onto the track at the Southern 500 and wrecked on the first lap, a close aide said today.

NASCAR, stock car's sanctioning body, said it wants to talk to Earnhardt, his car owner and his doctors before clearing the star driver to race again.Earnhardt underwent more hospital tests today in an attempt to determine what happened at the start of Sunday's race in Darlington, S.C., said Don Hawk, president of Dale Earnhardt Inc.

"Dale does not live in fear, but he's concerned," said Hawk, who runs the Mooresville marketing and racing company owned by the seven-time Winston Cup champion.

Hawk said no one in Earnhardt's pit became concerned when the 46-year-old driver nodded off while waiting for the race to start because the man known as "The Intimidator" is famous for his relaxed demeanor.

"It's not unusual for Dale to doze off before a race or under red-flag conditions," Hawk said.

Team members became suspicious, though, when Earnhardt fell asleep a second time. But by then the drivers were ordered to start their engines and begin the race.

After Earnhardt went out and hit the wall twice on the first lap, he had difficulty finding the entrance to pit lane and didn't respond immediately to radio commands from car owner Richard Childress in the pits.

"Richard screamed at him to park the car right now," Hawk said. "Dale said, `I'm sorry, I saw two racetracks.' "

Hawk would not say which hospital Earnhardt went to this morning.

"When the tests are completed, two of the finest medical institutions in America will take a look at the results," Hawk said.

NASCAR spokesman Kevin Triplett said the sanctioning body will not allow Earnhardt to drive at the next race - the Exide NASCAR Select Batteries 400 in Richmond, Va., on Saturday night - until it is satisfied he is fit.

Earnhardt was released Monday from McLeod Regional Medical Center in Florence, S.C., where tests found nothing wrong.

"I don't know what happened," Earnhardt said then. "I feel great now."

Earnhardt was carried like a rag doll to the Darlington Raceway's care center. He spent almost 24 hours undergoing tests at McLeod, all of which came back negative.

"He had CAT scans, an EKG, an MRI, they ran dye through his arteries, everything," Earnhardt spokesman David Allen said. "It's kind of baffling."

Allen said the tests did not show any symptoms of a heart attack or evidence one was starting.

Dr. Joseph Healy, a neurologist at McLeod, said additional tests were recommended for several reasons - Earnhardt's profession, past head injuries, and his father dying of a heart attack at age 44.

On Sunday, Earnhardt was replaced in the car by Busch Series driver Mike Dillon.