Ponca City, Oklahoma - Ponca City Energy is investigating a transformer explosion and fire at a city electrical substation Saturday morning.

The Ponca City newspaper reports the explosion at the facility on North Union caused a city-wide power outage. Service was restored to most customers within an hour.

The explosion was captured on cell phone video.  [LiveLeak.com]

According to the newspaper, Ponca City Energy, which runs the substation, says it is not sure how many electrical switches and other equipment was lost in the resulting fire.