Two-time NASCAR Cup Series champion Kyle Busch died Thursday from complications related to "severe pneumonia [that] progressed into sepsis," according to a family statement obtained by FOX Sports on Saturday."The medical evaluation provided to the Busch Family concluded that severe pneumonia progressed into sepsis, resulting in rapid and overwhelming associated complications," the statement, according to FOX Sports Bob Pockrass, read.This is a breaking news story. Check back for updates.Follow Fox News Digitals sports coverage on X, and subscribe to the Fox News Sports Huddle newsletter.