The Manchester Police Department said in a Facebook post the incident happened at the intersection of State Highway 70 and Colonial Drive in Manchester Township, located about 60 miles south of New York City.
"Last night was quite SHOCKING for some of our midnight officers!" the department said.
In video posted to Facebook, a utility worker is shown trying to handle a wire that was believed to be de-energized.
As the wire falls to the wet ground, it suddenly explodes into a fireball.
"Luckily, he was wearing proper safety equipment," police said.
Manchester Township Police Sgt. Christopher Hemhauser told WCAU-TV he and another officer had to flee earlier that night from the same intersection when an arcing transformer sent sparks flying.
He also witnessed the second explosion, and said the utility worker was "definitely startled."
“It’s just a reminder of how dangerous electricity really is,” he told the television station.
Manchester Police said no one was injured in either incident. A spokesperson with Jersey Central Power and Light told WCAU the incident is under investigation.