PUYALLUP – Three Tacoma-area power substations were vandalized early Christmas morning, officials said Sunday, cutting off power to more than 14,000 people in eastern Pierce County.

The Pierce County Sheriff’s Department is investigating whether the incidents were coordinated and whether they could be connected to a string of recent attacks on power substations around the country by right-wing extremists.

Sgt. Darren Moss Jr. said the department received a burglary call at a Tacoma Power substation in Spanaway shortly after 5 a.m. When deputies arrived, they saw forced entry and vandalized equipment that caused a loss of power. A Tacoma Power substation in Graham revealed a similar scene: forced entry and damaged equipment.

The department also received a call from Puget Sound Energy later Sunday morning advising of another power outage at 2:39 a.m. from a third facility in Puyallup. Deputies at that scene said the facility had been broken into and vandalized. That outage lasted around 30 minutes and power has since been restored, said Moss.

Nothing was taken from any of the substations, Moss said. He declined to say which pieces of equipment were damaged, citing an ongoing investigation.

The Pierce County Sheriff’s Department said it’s unknown if there were any motives or if “this was a coordinated attack on the power systems.” Moss said he wasn’t sure how many suspects were involved.

Tacoma Public Utilities called the incidents at its substations “attacks,” but offered scant details.

“Deliberate physical damage occurred at two of our substations,” Tacoma Public Utilities spokesperson Rebekah Anderson said by email.

Sunday marked the latest incidents in a string of attacks on electricity substations in Washington and Oregon this winter. The motives are unclear. But energy experts have warned the power grid is a prize target for domestic terrorists.

A U.S. Department of Homeland Security memo warned in January that extremist groups have been creating “credible, specific plans” to attack power facilities since at least 2020. This month, two North Carolina electricity substations were shot up and damaged, causing thousands of people to lose power.

The damage to the Pierce County substations didn’t appear as extensive. Moss said the equipment didn’t show signs of firearm damage.

Puget Sound Energy, the Cowlitz County Public Utility District, Portland General Electric and the Bonneville Power Administration told the Seattle Times they were cooperating with a federal investigation after substation attacks in November.

One of the attacks occurred over the Thanksgiving holiday. A fence was cut and equipment damaged at a substation in Clackamas, Oregon, according to the Bonneville Power Administration.