On Wednesday at about 4:30 p.m., approximately 350 businesses and residents found themselves without power moments after a loud blast sounded in downtown Oak Harbor.

“I was walking and I heard a big boom,” said Oak Harbor resident Maggie Lee, who heard the sound from Swantown Road.

Shortly after the sound, most of downtown Oak Harbor and the surrounding residential areas lost power.

The Oak Harbor fire and police departments responded quickly to the sound and power outage, not knowing if the cause was a blown transformer or an accident.

Police Chief Steve Almon said the sound was called in as a traffic accident, but upon investigation, police officers did not find any accidents throughout Oak Harbor.

Even without an accident, however, Police officers still had their hands full directing the 5 p.m. home-bound traffic left without traffic lights.

Approximately a half an hour after the electricity in the downtown area shut off, most of it came back on.

Lynn Carlson, spokeswoman for Puget Sound Energy, said the company had received information about the power outage in Oak Harbor shortly after it happened. She said it was not, however, a blown transformer because a blown transformer would have taken longer than a half an hour to fix.

Instead, she said the boom and the power outage were most likely the result of a short circuit in a lightning arrestor downtown.

A lightning arrestor is a device used on poles, wires, cables, transformers, buildings and electrical equipment to protect them from power surges, lightning and high voltage by carrying the charge to the ground or providing an alternative path for the energy to follow.

“It is not a usual thing,” Carlson said.

By 6:45 p.m. Puget Sound Energy had restored all the power to the affected businesses and homes in and around the downtown Oak Harbor area.