It caused sparks to fly out of a grate Wednesday night near the intersection of Green Lane and Ridge Avenue.
Cynthia Singer was driving down the road, then decided to turn around.
"I was just exploding. It was coming from the ground. My first impression was that it was a transformer, but it didn't make sense because transformers are usually up."
Utility crews responded to the area Thursday to restore power to an unknown number of customers.
PECO says this was an isolated incident and the area around the grate is safe.