surface to air lightning strike It happens more with improper grounding but corrosion also plays a roll if it was a fire the pine needles would be burnt If someone lit a fire it was while the sprinkler was running or it was raining Why would you need a sprinkler for weeds. in most cases when it rains you get lightning jmo but seen it more than twice but looking at the pic someone stole the copper ground or it would be hanging from the green plastic path of least resistance comes into play
