Kyle Busch suffered a tragic chain of events leading to his death at age 41.

According to a death certificate obtained by Us Weekly, Busch had been battling bacterial pneumonia for “days to weeks” before developing sepsis.

The sepsis caused disseminated intravascular coagulation — small clots that form in the bloodstream — which blocked blood flow to his organs. He then suffered hemorrhagic shock, resulting in severe internal and external blood loss, which ultimately led to his death on May 21.

Signs of trouble emerged the previous week when Busch appeared unwell on May 15, shortly after winning the NASCAR Craftsman Truck Series ECOSAVE 200 at Dover Motor Speedway.

He was hospitalized on May 20, with his family issuing a statement that he was dealing with a severe illness and would be withdrawn from all racing activities that weekend.

The day before his death, Busch was found unresponsive in a racing simulator. A 911 call obtained by The Post reported that the racer was lying on the bathroom floor “coughing up blood” at the General Motors Charlotte Technical Center in Concord, North Carolina.

Busch is survived by his wife, Samantha, and their two children — son Brexton, 11, and daughter Lennix, 4.

The superstar racer was one of the most dominant drivers of his era. A two-time NASCAR Cup Series champion (2015 and 2019), he recorded 63 career Cup Series wins, tying him for ninth on the all-time list. In 2015, he famously won the championship after missing the first 11 races due to a broken leg and foot. He was also named NASCAR Rookie of the Year in 2005.

The racing world paid tribute to Busch over the weekend at the Coca-Cola 600 at Charlotte Motor Speedway and the Indianapolis 500.