Kyle Busch’s cause of death revealed by family

NASCAR star Kyle Busch died from severe pneumonia that progressed into sepsis, according to a statement released Saturday by his family.

“The medical evaluation provided to the Busch Family concluded that severe pneumonia progressed into sepsis, resulting in rapid and overwhelming associated complications,” according to the statement from the Busch family. 

Busch, who won more races in NASCAR’s top three series than anyone in history, died suddenly on Thursday after passing out a day earlier in a driving simulator at General Motors facility in Concord, North Carolina.

Sepsis is a life-threatening medical condition that occurs when the body has an extreme response to an infection, causing damage to tissues and organs, according to the Centers for Disease Control and Prevention.

The 41-year-old experienced shortness of breath, felt he was overheating and was coughing up blood the day before his death, according to a 911 call obtained Friday by CBS News.

This was the Busch family’s first statement since Thursday, when they wrote on social media that he “experienced a severe illness resulting in hospitalization” and would miss this weekend’s Coca-Cola 600, one of the biggest races of the season.