NASCAR driver Kyle Busch died from severe pneumonia that turned into sepsis, according to a statement provided 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," said the family statement, which was released on Saturday, local time."The Family asks for continued understanding and privacy during this difficult time."Dakota Hunter, vice-president of Kyle Busch Companies, said the family received the medical evaluation on Saturday.Busch, a two-time NASCAR Cup Series champion considered one of the best drivers of all time, died Thursday He was 41.The Busch family, Richard Childress Racing and NASCAR confirmed his death hours after announcing that Busch had been hospitalised this week and would miss Sunday's Coca-Cola 600 at Charlotte Motor Speedway.Busch experienced shortness of breath and was coughing up blood the day before his death, according to a 911 call obtained on Friday by USA Today.He is survived by his wife Samantha, 11-year-old son Brexton and 4-year-old daughter Lennix