A fire atop an electric utility pole next to River Park Hospital left the eastern part of McMinnville in the dark Monday afternoon.“It affected approximately 333 customers,” said McMinnville Electric System general manager and CEO Rodney Boyd, dispelling the myth it was a transformer that blew up during the heavy rain storm around 4 p.m. Monday. “It wasn’t a transformer. It was an oil switch that caught fire.”Witnesses reported hearing an explosion and seeing fire atop the utility pole that was located next to River Park Hospital.