What caused the series of explosions during a power failure?

[wolram]

My lights stated to flash on and off at the same time i noted a series of bangs coming from outside, as i looked through the window i saw small explosions with puffs of smoke and debris traveling along the overhead power cable, it seems a tree branch had severed the cable, but why so many explosions along the line, there must have been 20 or so, before
the fuse went, my neighbour said it looked like a firework display from his house.

 

[Evo]

Squirrels exploding along the lines.

 

[Ivan Seeking]

Those lines are intended to carry a high currents at [probably] 12,500 volts or so. It may be that the circuit hadn't shorted out hard enough to trip the supply.

 

[wolram]

Squirrels exploding along the lines.

You can have my award, that actually made me laugh.

 

[wolram]

Those lines are intended to carry a high currents at [probably] 12,500 volts or so. It may be that the circuit hadn't shorted out hard enough to trip the supply.

I guessed it was some thing like that, the interesting part was watching the explosions run along the line getting ever closer to to the break, may be ohms law will explain it, but i can not think how yet.