The contact owns a 2019 BMW X3. The contact stated that the carbon monoxide detector sounded an alarm from the living room. The contact stated that her husband was unable to turn off the carbon monoxide alarm and called the Fire Department. The Fire Department arrived and determined that the vehicle, which had been parked in the garage of the residence, had experienced a thermal event in the engine compartment. The contact was advised that heat had generated carbon monoxide gas that had spread from the garage into an attic crawl space and then into the living room of the residence which had set off the carbon monoxide alarm. The contact stated that they were not able to drive the vehicle out of the garage due to the heat from the engine compartment. The contact stated that after the Fire Department had cleared the garage and residence of carbon monoxide, the contact was able to drive the vehicle out of the garage. The contact was advised by the Fire Department that the temperature in the engine compartment was getting dangerously hot and the vehicle was turned off. The contact had not taken the vehicle to a local dealer or independent mechanic. The vehicle was not diagnosed or repaired. The contact stated that the week prior to the failure, the vehicle was at a dealer for the water pump replacement. The manufacturer was not informed of the failure. The failure mileage was approximately 100,000.