Il Nuovo Postiglione - NASCAR boss pays tribute to 'badass' Kyle Busch

O'Donnell spoke to reporters in Charlotte, North Carolina, where he said that after some discussion the Coca-Cola 600 will go ahead as scheduled on Sunday.

"Kyle Busch would probably be pretty pissed off if we didn't race," O'Donnell said. "So we're going to honor his memory and make sure people know what he was all about."

Busch, who was in his 22nd season in NASCAR's top division, died on Thursday after he was hospitalized with an undisclosed "severe illness".

His family asked for privacy and O'Donnell said that out of respect for them he was not going to answer questions about Busch's health or cause of death.

Some details had begun to emerge as US media gained access to a 911 emergency call for an ambulance, which was made Wednesday from the General Motors training facility in North Carolina.

The caller told the dispatcher that the individual in question, Busch, had shortness of breath, felt hot and was "coughing up some blood".

O'Donnell said he'd received a phone call on Thursday morning telling him "things weren't great" with Busch.

His family and his Richard Childress Racing team had announced Busch's hospitalization and withdrawal from Sunday's race Thursday morning and hours later announced his death.

"Out of respect for the family, and they've asked for privacy, I'm not going to address any of that," O'Donnell said.

Instead he focused on Busch's legacy in a sport he approached with passion.

"At the end of the day, he would always have an opinion, but it always came from a place of trying to improve the sport," O'Donnell said.

"This sport is a badass sport. Kyle Busch, to me, is an American badass. We certainly had our battles, but I would give a lot of money to have a few more battles going forward."

O'Donnell's comments echoed the heartfelt tributes from Busch's stunned NASCAR colleagues.

Dale Earnhardt Jr, an on-track rival involved in several on-track incidents with Busch later became a friend.

"Kyle and I had a really challenging existence for many years," Earnhardt said in a social media post, calling Busch "one of the greatest drivers in NASCAR history".

"But we luckily took the time to figure out our differences and that was something he instigated with a conversation in his bus around how we each managed our racing teams.

- 'Heartbroke' -

"I was super eager for us to get on better terms. But it was he who made the effort for that to be possible. I will never be able to make sense of this loss, but I am thankful that we had found a way to become friends."

The fiery Busch also famously feuded with driver Joey Logano, the two coming to blows on a pit road in Las Vegas in 2017.

"Heartbroke," Logano said of his reaction to Busch's death in an interview with Charlotte television station WCNC.

"The bottom line is he is one of the best drivers ever to sit in a race car. And he impacted our sport in so many ways, such a huge personality. It's a big reminder of how fragile life is."

Just how far Busch's influence extended beyond NASCAR was clear Thursday when the NHL's Carolina Hurricanes honored him with a video tribute and a moment of silence before their playoff opener against the Montreal Canadiens.

A foundation launched by Busch and his wife to support couples struggling with infertility saw donations rise on Thursday night, many for $18.08 in recognition of the number 18 and number 8 cars he drove and marked as given in Busch's memory.

T.Cusumano--INP