The NTSB determined the cause of the accident was an explosion of the center wing fuel tank, resulting from ignition of the flammable fuel/air vapors in the tank. The source of ignition energy could not be determined with certainty. Of the ignition sources evaluated by the investigation, the most likely scenario was a combination of a latent fault of an electronic fuel quantity indicating system component within the fuel tank, combined with a short circuit or other fault outside of the tank. This scenario would result in a high-energy electrical arc within the fuel tank that could ignite the flammable vapors.
The primary component - a Capacitive Fuel Probe while explosion proof on its own - could not handle the input of a 115V AC Input and produced a spark