MILTON-FREEWATER — Residents of Milton-Freewater went more than seven hours without power Wednesday, Oct. 16, after overnight rain caused an electrical arc in the system.

According to City Manager Chad Morris, the city learned of the outage at about 7 a.m. The outage affected the whole city, but it was back up around 2:40 p.m.

The dusty Oregon summer led to dirt inside the transmission lines, Morris said, which then allowed moisture inside them during the gentle rain, causing an electrical arc — a current that doesn’t follow its electrical path and instead jumps through the air — that burned the wire “almost completely in half.”

That fire affected three poles in one area, burning the top of at least one, he said. To do the repairs, other power companies had to de-energize their lines and reroute their power feeds, which took some time. The repairs themselves also took about three hours once the poles were de-energized.

On top of that, the city normally relies on two substations to deliver electricity to residents, but one is undergoing maintenance, so the entire city was running on one substation.

“It was just a perfect storm of a situation,” Morris said. “Most cases, this would’ve been fairly short instead of most of the day like it was.”

This event is not something expected to happen again any time soon, Morris said. A substation is turned off “not even once a year” normally, he said, and things lined up “just right” for the outage to happen.

When the lines were reenergized, there was an additional problem for parts of the city. Some residents were again without electricity because of a transformer that blew, Morris said at about 3:20 p.m. A blown transformer is a more typical reason for a power outage, he said, but he hadn’t learned the official cause. His best guess was it would be due to everything trying to turn back on at the same time after the outage.

“There is no evidence that it’s connected,” he said, “but it is possible.”

Morris said the city will be reviewing the outage — how it happened and why — to determine if there are changes to implement that could prevent a similar situation in the future.

“We really don’t like having power outages,” he said.