The Fourth of July power outage that plagued most of Waldo County, and some surrounding towns, was attributed to a "defective insulator atop a transmission structure in Brooks," according to Avangrid's Corporate Communications Officer Gail Rice.

"As of 4:33 p.m. on Wednesday, power had been restored to all 6,173 affected homes and businesses," she said in a July 5 email.

Avangrid is the parent company of Central Maine Power Co. The malfunction affected feed substations in Brooks, Thorndike and Unity, so the outage impacted four distribution circuits serving a large area, including parts of Albion, Brooks, Burnham, China, Dixmont, Freedom, Jackson, Knox, Monroe, Montville, Newburgh, Palermo, Plymouth, Swanville, Thorndike, Troy, Unity, Unity Plantation, Waldo and Winterport, Rice said.

Personnel in Avangrid's Energy Control Center first became aware of a problem at 3:09 p.m. Initially 6,173 homes and businesses were affected. By 3:53 p.m., power was restored to 1,654 customers; by 4:13 p.m. power was restored to another 4,507 and at 4:33 p.m., the last 12 customers were brought back online.

"Power restoration was completed in less than 90 minutes Wednesday afternoon by switching the feed through other transmission lines," Rice said.

When asked about outages as a result of grid-overload due to increased demand — July 4 was one of the hottest days of the year so far — Rice said, "Outages due to load are rare. We have had some very widely scattered outages due to load over the past few days, but load has been cause of only about 10 percent of outages during that period."