Problems at a Duke Energy substation left thousands without power for hours Monday morning, but, by the afternoon, service had been restored.

The Forest Hills substation along Highway 254 at Deadfall Road had all three of its circuits go down Monday morning, said Theo Lane, Duke government and community relations district manager.

“We’ve been doing upgrades and working in that area the past several weeks,” he said.

The outage left more than 4,000 customers without power, including Greenwood High School and Hodges and Pinecrest elementary schools. The G. Frank Russell Technology Center also lost power, but students attending classes there were kept at their home schools, said Greenwood County School District 50 spokesman Johnathan Graves. Students were safe and provided lunch, and the schools returned to a normal schedule once power was restored.

Contact staff writer Damian Dominguez at 864-634-7548 or follow on Twitter @IJDDOMINGUEZ.