Our Nest Protect woke us at 06:30 am saying it was detecting smoke in the garage. Upon entering the garage it was obvious that the cabin of the car was filled with white smoke. Disconnected car from charger port. Attended to drive car out of garage to protect the house, but opening the door just let smoke billow out. Closed the door and called 911. Fire truck arrived - the winched the car out of the garage to protect the house. Using their thermal imaging camera determined the hybrid battery was the hotspot, not any of the charging connections. They ran water into back seat where that battery is located for over two hours to keep it from pop further thermal runaway. Clearly an internal EV battery short. Fire fighters had a sensor and detected residual HCN (hydrogen cyanide gas) and I had to be treated at the ER as a precaution as I inhaled a large amount of smoke when I opened the car door initially.