Kyle Busch dies at 41 after NASCAR driver hospitalized with 'severe illness’

Editor's note: The original version of this story was written before news of Busch’s death. It has been updated to reflect his passing.

Veteran NASCAR driver Kyle Busch died Thursday after previously being hospitalized with a "severe illness." He was 41.

Busch's family announced earlier Thursday that he had been hospitalized and would not race in Sunday's Coca-Cola 600 but did not disclose the nature of his illness, only saying that the driver was undergoing treatment.

Busch raced as recently as Sunday, when he participated in the NASCAR All-Star race, and he just won a NASCAR Truck Series race on Friday, six days before his death. Days earlier, Busch requested medical attention during a Cup Series race at Watkins Glen after reportedly battling sinus-related symptoms. 

On Saturday, the Busch family released a statement, describing Busch's illness as "severe pneumonia" that progressed into sepsis.

Here's what you need to know about Busch's illness after his tragic and sudden passing on Thursday.

What happened to Kyle Busch?

Busch's family first released a statement Thursday revealing the 41-year-old "has experienced a severe illness resulting in hospitalization."

Reports later Thursday indicated Busch was first hospitalized on Wednesday after becoming unresponsive. TMZ obtained the 911 call placed on Wednesday, which revealed Busch was experiencing shortness of breath and overheating as well as coughing up blood. Busch was awake and responsive at the time the call was placed.

Busch won the NASCAR Truck Series race in Dover on Friday, six days before his illness was disclosed, and raced in the NASCAR All-Star race on Sunday. In his last Cup Series race on May 10, Busch at one point requested medical attention after reportedly battling a sinus infection in the week leading up to the race.

Kyle Busch illness

On Saturday, May 23, the Busch family released a statement that said a medical evaluation concluded that Busch's "severe pneumonia progressed into sepsis, resulting in rapid and overwhelming associated complications," per Jeff Gluck.

The Busch family originally only called the illness "severe," explaining that it required hospitalization. The original announcement was made about seven hours before the news of Busch's passing.

Busch became unresponsive while testing in the Chevrolet racing simulator on Wednesday and was taken to a hospital, the Associated Press reported, before passing away on Thursday. TMZ, citing the 911 call placed at the Chevrolet testing facility, reported that Busch experienced shortness of breath and overheating, also coughing up blood, before he was taken to the hospital.

Us Weekly obtained Busch's death certificate, which revealed the driver battled pneumonia for days to weeks before it progressed into sepsis. Sepsis led to small clots, which blocked blood flow and resulted in hemorrhagic shock from severe blood loss.

Busch was a two-time NASCAR Cup Series champion and 63-time winner across 23 seasons, becoming one of the most recognizable drivers of his generation along the way.

Kyle Busch 911 call

Audio of the 911 call placed at the Chevrolet testing facility in Concord, North Carolina, revealed that Busch was experiencing shortness of breath and overheating before being hospitalized on Wednesday evening.

Busch was also coughing up blood and felt like he was going to pass out, according to the audio obtained by TMZ, but he was said to be awake and responsive at the time. The NASCAR legend was on the bathroom floor, the caller said, as he awaited paramedics.

The caller also requested that paramedics turn off their sirens while approaching the facility.