I was working with a power company connecting generators to services while the power company made changes to the system. It was a while ago but if I recall they where switching from delta to wye distribution and doubling the voltage. They had spent a lot of time preparing and placing new transformers all over the place then they powered down and cut everything over ......... except they missed one and they told me they sent the homes on that transformer 240/480 instead of 120/240.
Anyway I went with a power company worker into a guys home, he lost a lot of crap, entertainment equipment, blown Edison base fuses, GFCI duplex burned up pretty impressively.
The power company guy was handing out his business card to the homeowners on that transformer and told them to call with a list of damages.