The Busch family, Richard Childress Racing and NASCAR issued a joint statement saying that Busch died after being hospitalized earlier in the day as the result of a severe illness, three days before he was to compete at the Coca-Cola 600 at Charlotte Motor Speedway. No cause of death was given.

"On behalf of the Busch family, everyone at Richard Childress Racing and all of NASCAR, we are devastated to announce the sudden and tragic passing of Kyle Busch," NASCAR said in a statement. "Our entire NASCAR family is heartbroken by the loss of Kyle Busch. A future Hall of Famer, Kyle was a rare talent, one who comes along once in a generation. He was fierce, he was passionate, he was immensely skilled and he cared deeply about the sport and fans."

Busch was testing in the Chevrolet racing simulator in Concord, North Carolina, on Wednesday when he became unresponsive and was transported to a hospital in Charlotte, several people familiar with the situation told The Associated Press on condition of anonymity because details had not been disclosed by Busch's team or family.

Busch, the younger brother of NASCAR Hall of Famer Kurt Busch, is survived by his wife, Samantha, and children, Brexton and Lennix.

The news comes 11 days after Kyle Busch radioed into his crew near the end of a Cup Series race at Watkins Glen asking a doctor to give him a "shot" after he finished the race. According to the television broadcast, Busch had been struggling with a sinus cold that was exacerbated by the intense g-forces and elevation changes at the New York road course.

Busch finished the race in eighth place.

Busch competed at Dover last weekend and won the Truck Series race for Spire Motorsports. He finished 17th at the NASCAR All-Star race with Richard Childress Racing.

"Absolutely cannot comprehend this news," NASCAR driver and former teammate Denny Hamlin posted on social media. "We just need to think of his family during this time. We love you KB."

Added veteran NASCAR driver Brad Keselowski on X: "Absolute shock. Very hard to process."

Busch ranked 24th in the Cup Series standings this season, with two top-10 finishes in 12 races. The Las Vegas native won championships with Joe Gibbs Racing in 2015 and 2019. Busch was in his fourth season at Richard Childress Racing.