BROOKLYN, Mich. — Tony Stewart opened his remarks with a few words about his relationship with Jason Leffler.

Moments later, he offered a brief plea amid growing safety questions about Leffler's death at a dirt-track race earlier this week.

"I'd be grateful if you guys would understand that what happened this week wasn't because somebody didn't do something right with the race track. It was an accident. Just like if you go out and there's a car crash. It's an accident," Stewart said Friday at Michigan. "Nobody as a track owner wants to go through what happened this week, but it's not due to a lack of effort on their part to try to make their facilities as safe as possible under the conditions they have."

Leffler died Wednesday night from injuries suffered in a sprint car crash at Bridgeport Speedway in Swedesboro, N.J. The Delaware County (Pa.) medical examiner determined Leffler died from a blunt force neck injury. He was 37 and is survived by a 5-year-old son.

Stewart knows all about the challenges facing track owners. He owns Eldora Speedway in Ohio, a dirt track that will host a NASCAR Truck Series race next month. He's one of a handful of big names who will show up to race at small, local tracks from time to time, but Leffler's death brought renewed attention to the safety of those races — and not everyone is optimistic.

"I don't run those races for a reason. I have teams, yes, certainly. There are a handful of drivers that run at the local level. I don't very often," said Brad Keselowski, the defending Sprint Cup champion. "I don't know what happened to Jason, and maybe it was completely unrelated, and I don't want that to be confused, but still, the safety standards at local short tracks — they're out of control. They're dismal."

Sprint car races can be more dangerous for drivers and spectators because many facilities lack the SAFER barriers that are standard in NASCAR and IndyCar, and the cars aren't always adequately protected. Bridgeport Speedway does not have SAFER Barriers, energy-absorbing walls cost about $500 a foot for installation. Most local short tracks cannot afford them.

Stewart said safety is improving, though.

"Most of them have safety teams at each facility. ... That's probably the one thing I've seen the most of is having adequate safety teams there and making sure they can respond to the problem pretty quick," Stewart said. "I think things are the best they've ever been at this point. There's facilities that need some work and there's facilities that put a lot of effort into it."

Tom Deery is president of World Racing Group, which sanctions dirt track racing in the United States and Canada. He said there have been advancements in seat and seat-belt technology, and lot of safety improvements can filter down from the Sprint Cup level.

Not fast enough for Keselowski.

"They don't have the safety standards that we have here in NASCAR. That's not to say that all tracks in NASCAR have it right, either. ... but it's even 100 times worse at the local level," Keselowski said. "It's funny, because I talked to my dad, who raced local short tracks, and every once in a while, we'll talk about some track that he went to with my brother or whatever situation, and I'll ask him how it was. And he'll tell me, 'Well, it hasn't changed since 1975 when I was last there.' I'm pretty sure safety has taken some pretty big leaps forward since 1970-something."

Deery took exception to that comment, and said owners of these small tracks likely would, too, especially since so many have a personal stake in the venue's safety.

"Probably more often than not, they either have a family member that participates or they participate there themselves," Deery said.

Leffler was remembered by drivers for his love of racing and his willingness to get behind the wheel in so many different formats. Keselowski raced with Leffler on the Nationwide Series. Like many NASCAR and IndyCar teams this weekend, he has a #LEFturn decal on his No. 2 Ford in Leffler's honor.

In a sport that may never be 100 percent safe, drivers will return to these smaller, off-the-beaten-path tracks. The passion for racing helps overcome any fear of danger — and some of NASCAR's top drivers still view sprint car racing as an enjoyable getaway.

Stewart started his career on dirt tracks in Indiana, and he makes select appearances at dirt tracks in addition to his Sprint Cup schedule.

"It's just something different. I get to race with the best stock car drivers in the world every weekend here for three days a week," Stewart said. "In the evenings I get to go do something that's the polar opposite end of the spectrum, and it's a challenge because it's the opposite end of the spectrum for us. They're 910 horsepower cars that weigh 1,400 pounds. It's probably the best power-to-weight ratio other than a motorcycle."

Kasey Kahne came through the sprint car ranks, still races when he can and fields several cars through Kasey Kahne Racing.

"As far as our teams go, I talked to all of them yesterday. We do as much as we can with sprint cars, with the safety, with trying to have the best seats just to contain you left, right, shoulders," he said.

Kahne flew last weekend with Leffler to Pocono Raceway, where Leffler made his only start of the Sprint Cup season. Kahne has said this week how excited Leffler was to have plans to race on multiple nights this week.

"Things still happen. It's racing," Kahne said. "It's basically anything we do, any one of us does each day, it can happen. I just feel for his family and his son."