From the number of customers affected this would have, in all probability, been an 11,000V or 6,600 volt line on wood poles, these will have been below 45ft in height.
As the wires are all below about 15mm in diameter and down to 5mm they don't show on NVG apparatus (we have trialled it to find faults at night).
The sheer amount of lines at these voltages would make it too big a task to put them all on GPS.
As an example the area I work in is about 1300 square kilometers, we have about 1700km of lines of these voltages