General Motors' position on the fire is that the battery should have been drained after NHTSA crash-tested the car, a preventative measure the automaker says it recommends.
NHTSA's inquiry involves other carmakers who use lithium-ion battery packs, not just GM. According to the report, the agency is reviewing the automaker's responses, which likely pertain to the feasibility of requiring first-responders to drain battery packs. The Detroit Free Press says GM must currently deploy a team to drain Volt batteries, though a GM spokesman says a tool to drain batteries may become available to dealerships next year.
The safety of electric vehicle batteries and the unique dangers they pose to first responders have been an ongoing concern since the first hybrids hit the market over a decade ago. The market's shift toward lithium-ion batteries and an increase in the size of battery packs have only drawn the issue into starker focus.