re: bill and clifford's points - I hadn't really thought about that before but that explains something.
I had a nissan stanza fry itself due to an electrical fault.  When it started happening I pulled every breaker.
That didn't help.  I emptied 3 fire extinguishers into the engine compartment (the big industrial kitchen size).
That didn't help.   Someone had the presence of mind to rip one of the battery leads off the lug with their
bare hands.  That helped.

When it was all over I had a 3" hole burned through one fender, the entire wiring harness throughout the car was junk.
I wouldn't want this to happen in an airplane.
I never found the source but apparently there was some wire that wasn't protected.