BREWER – A blown insulator was cited as the cause of a power outage late Thursday that affected Bangor Hydro-Electric Co. customers in Brewer, Holden, Orrington and Bucksport.

The outages began about 10 p.m. Reports from affected customers began appearing on the outage section of the company’s Web site almost immediately.

Bangor Hydro spokeswoman Susan Faloon said that the blown insulator, located at the Tibbetts Street substation in Brewer, knocked power out to 5,345 customers. She said power likely would be restored within about an hour, barring any unforeseen snags.