Apparently something blowing around in the wind made contact with a power switch to start the massive fire in Gangwon-do:

The state-run Korea Electric Power Corporation (Kepco) announced that the fire seemed to have been sparked by a power switch at a gas station in Goseong, just miles south of the border with North Korea. According to Kepco, “an alien substance” blown by the wind caught on an electric wire connected to a power switch, causing a spark, which grew into a fire.
Joong Ang Ilbo
No further detail was given about the unidentified substance.
You can read more at the link, but shouldn’t there be better fire prevention measures around these power switches to where something blowing in the wind doesn’t start a fire?