The National Highway Traffic Safety Administration announced November 25 that it will open a formal safety defect investigation into fire risks involving General Motor Company’s Chevrolet Volt electric vehicles. The inquiry comes after recent testing showed evidence that damage to the car’s lithium ion battery during a crash could cause a fire days or weeks afterward. The NHTSA is working with the Departments of Defense and Energy as well as GM to assess the cause of the latest fire, but it is too soon to tell whether the investigation will lead to a recall of any vehicles or parts.