KPU crews work on downed power lines in the Refuge Cove area in this 2016 file photo. (Leila Kheiry/KBRD)

Ketchikan, Wrangell and Petersburg lost power in the early morning hours of the Fourth of July — and a bird may be to blame.

The three-island blackout began around 3 a.m. and ran until just after 8 a.m. Saturday. In Ketchikan alone, the outage affected more than 9,500 homes and businesses.

Ketchikan Public Utilities’ Jeremy Bynum said that a bird strike likely caused the power failure, rather than weather or an equipment fault.

“It could have been an eagle, it could have been a raven, it could have been some other kind of mammal like a squirrel,” Bynum told KRBD Monday. “It could have been an eagle dropping a fish carcass onto the lines, we’ve seen that happen before.”

Bynum said it takes a unique series of events to knock out power for all three islands: the bird would have to land on transmission lines connecting power-generating dams to the wider grid.

Ketchikan is tied into Wrangell and Peterburg’s electric grids via the Southeast Alaska Power Association, a power wholesaler that operates two major dam projects in southern Southeast, including one in Ketchikan. If a connection to one of those dams is interrupted — by, say, a bird slamming into transmission lines — that can knock all three towns offline.

But large-scale blackouts like these are rare, according to Bynum — he said the last one occurred in 2017.

“I mean that’s not really common. And the truth is that this was actually one of our longer outages that we’ve had in a long time,” he said.

Bynum said KPU can usually fix outages in less than two hours, but big blackouts that affect the entire island require a large crew and take longer to fix. Last weekend’s outage took about four hours to restore.

The outage is still under review to determine a full sequence of events.

This story has been updated.