FARMINGTON — About 4,000 customers in Franklin County lost power this morning when a mobile substation in Farmington malfunctioned, forcing businesses to close and schools to dismiss students early.

Power went out primarily in Farmington and small pockets of several nearby towns about 8 a.m., according to Central Maine Power Company. Utility crews restored power shortly before noon and began looking for what caused the mobile substation to fail, company spokeswoman Gail Rice said.

Businesses in downtown Farmington had signs telling customers about the closings, while motorists turned a nearby intersection with unlit traffic lights into a four-way stop.

Students at Mt. Blue High School were dismissed at noon due to the outage. Students at W.G. Mallett School were bused to Cascade Brook School in Farmington for lunch and returned to their building after the power came back, according to the Mt. Blue Regional School District 9 website.