Local authorities are currently investigating the source of the re-ignition, though some members of the media-at-large have been quick to single out the Volt as the cause of the first fire, even though fire investigators have yet to speak up with their findings.
General Motors, meanwhile, is sending its own experts to investigate both incidents. The automaker originally issued a statement urging the public to refrain from leaping to conclusions about the first fire, asking everyone to allow local authorities and the automaker's own engineers time to uncover the origin of the trouble. You can find the full statement here. Thanks for the tips, Kris and Phil!
[Sources: WTNH, WFSB]