Greg Biffle spent Monday night visiting the widow of Hendrick Motorsports chief engine builder Randy Dorton, one of 10 people killed Sunday when a company plane crashed on its way to Martinsville (Va.) Speedway.

Biffle spent Tuesday testing at Darlington (S.C.) Raceway.

“It’s pretty tough,” said Biffle, who became close to Dorton and his wife, Dianne, during the past ninth months even though he drove for competitor Roush Racing. “It’s been really hard for me to have any energy to even come down here and get back going again.”

Such is the life of a NASCAR driver.

Such is the life of anybody associated with the sport.

“These are things we have to do here,” Biffle said. “We have to test. We have to move on. We have to keep going.

“I remember when Dale Earnhardt was killed in Daytona in 2001, we had to go test in Atlanta on Monday and Tuesday. We went and tested for one day and came home.”

Jeff Burton welcomed a return to the track. He said getting behind the wheel took his mind off the tragedy, which took the lives of the son (Ricky), brother (John) and twin nieces (Jennifer and Kimberly) of Hendrick Motorsports owner Rick Hendrick.

“In this spin cycle we’re going through … we hear of fatalities in the sport, a day later we’re at a racetrack testing,” he said. “We’ll go to funerals on Thursday. A day later we’ll be at the track qualifying.

The day after the crash of a Hendrick Motorsports airplane, racing fans left flowers, cards and other mementos to honor the victims at the company's headquarters in Concord, N.C. Company employees attended meetings where grief counseling was offered.

“It’s difficult to do. At the same time, it gets your mind on to the next thing. We have that advantage. The families don’t. We’ve got to find a way to help the families through it.”

Burton called Sunday’s tragedy the “biggest disaster” the sport has seen in his lifetime, bigger than the death of Earnhardt.

Biffle agreed.

“I don’t want to compare it to Earnhardt’s death by any means, but this is probably a more significant loss to the NASCAR community because it was so many people,” he said. “Dale Earnhardt obviously was the biggest loss that our sport could suffer.

“But behind the scenes, the 43 teams that show up in this garage and work in the shop every week, we lost a bunch of people in key positions. Everybody can relate to Ricky. I raced with Ricky for two years. There’s not one guy in this garage that didn’t know Randy Dorton.”

Dorton and his wife had become close friends with Biffle, Matt Kenseth and their spouses. The six of them went to dinner at least once a month at Red Rocks in Birkdale just outside of Charlotte, N.C.

“If you knew Randy, he was one of the nicest guys you would ever want to meet,” said Kenseth, who also was testing at Darlington.

Biffle said Dorton was unlike anybody in the sport because of his genuine personality and his uncanny way of getting power out of an engine. Biffle became emotional when recalling something Dianne told him on Monday night.

“She said, ‘He really cared about you,'” Biffle said. “‘He said he couldn’t talk about you at work because he works for Hendrick, but he always had his eye on you and was watching you like you were one of the cars he works on.'”

Burton was close to Dorton and Ricky. He had been fishing several times with Ricky and was “impressed with him as a person.”

“That’s typical of Hendrick Motorsports and the Hendrick family,” he said. “They tend to surround themselves with good people.”

Burton wouldn’t be surprised if this tragedy propelled Hendrick driver Jeff Gordon, who is second in the championship chase and 96 points behind Kurt Busch, to his fifth title.

“Jeff Gordon has exhibited over a long period of time to be the utmost professional,” he said. “Knowing Jeff Gordon, I wouldn’t be surprised to see this springing him into running better than they’ve been running.”