Concerning details have begun emerging about the sudden and tragic death of former NASCAR great Kyle Busch.

911 audio obtained by TMZ Sports reveals that Busch, 41, was coughing up blood the day before he succumbed to what is being described as a “severe illness.”

The call, placed at 5:30 PM local North Carolina time, provides a detailed account of the seriousness of the medical event affecting Busch, with the caller describing the driver’s breathing as labored and saying the 41-year-old was coughing up blood and overheating.

“I’ve got an individual that’s shortness of breath, very hot, thinks he’s going to pass out, and he’s producing a little bit of blood, coughing up some blood,” the caller explained.

The caller added, “He is awake. He’s awake. He’s awake.”

Repeated pleas were made for ambulances to respond to the testing facility at Richard Childress Racing, where Busch was lying on the bathroom floor.

Busch was found unresponsive while testing a Chevy racing simulator only a day before. He is survived by his wife, Samantha, his 11-year-old son, Brexton, and his 4-year-old daughter, Lennix.