Oof,
Yeah, that's a catastrophic failure. On the plus side it looks like they are (relatively) near civilization.
Not sure how the conversion was performed, but basically with a single wheel you have a smaller contact patch that is further away from the center of the bearing. Every time you hit a bump in the road it transmits more force to the bearing than the dual wheels (larger contact patch, centered over the bearing) which can lead to premature failure.
Generator was locked up (not that it would stop someone) and other items were out - they may have been close by, but we were around for a while and didn't see anyone.I'm surprised they would leave their generator out in the open if they went into town.
Jason