Excerpt:
The incident happened in Texas. Photo was taken by the volunteer fire department. A utility power line landed on a gas meter. Current found its way to ground through the water heater. National electrical code requires that gas lines be bonded to a grounding electrode conductor if it is likely that the gas line become energized. If this gas line had been properly bonded using a 6 AWG wire (minimum), then the utility fuse would have tripped and opened the utility power.