On Friday, September 4, 2015 at 1:24:29 PM UTC-7, David Farber wrote:

Wouldn't all of the current have to go through the shorted diodes (1N4007)
and shouldn't they show some sign of physical destruction? Other than being
electrically shorted, they were physically unscathed.

If a diode fails short circuit, it can be lower resistance than associated wiring
or fuses (i.e. it cooks everything else in the circuit, but stays cool).