The probe is in response to a Chevrolet Volt that caught fire. It happened while the Volt was parked at a National Highway Traffic Safety Administration testing center weeks after it was put through a side-impact crash test. GM says testers did not follow proper procedures for handling the Volt following a crash.
Based on testing so far, safety regulators believe the lithium-ion car batteries are safe. Still they are asking automakers about the batteries risk for fires.