Not that this would necessarily have made much difference, but the power lines should have been moved underground years ago - at least in the stretch at the end of the runway.
I'm afraid I can't remember the voltage used - that found across the top outer wires - but I'm fairly sure it's in the thousands. It's hard to bury that kind of voltage, and to drop it, and then raise it again, would be horribly expensive.
I'm kind of puzzled. Even using say, 4,000 volts, the amount of power used by an airfield would be vastly more than those lines could carry - even if they came in from four different directions and then combined.
I think it's more likely the lines were shorted and that shut down some larger sub-station. That should mean the main power could be reinstated fairly quickly. Possibly.