The Pierce County Sheriff's Department said robberies were reported at two substations belonging to Tacoma Public Utilities and another belonging to Puget Sound Energy. Deputies cited forced entry into the fenced-in area, with equipment vandalized but nothing taken from the sites, it said. More than 14,000 customers were affected.

"At this time deputies are conducting the initial investigation. We do not have any suspects in custody. It is unknown if there are any motives or if this was a coordinated attack on the power systems," the department said in a statement on its website.