That was an X not a Y, and there've been pictures of at least two others. One was at an apartment and another was in a ditch near some sort of vehicle repair shop.

I don't have time now, but the 10 figure came from a report with official sources. I suspect it was pretty close to right.

I don't know how it compares to gas car fires, which are also not uncommon after submersion in saltwater. Often the reason is the same too, the low voltage battery sometimes catches fire.