White Bluffs Elementary School in Richland lost power about 1 p.m. Thursday.
Phones, computers and HVAC systems were down for the afternoon, said district spokesman Steve Aagaard. Officials decided to keep children in class because the school building was holding in the heat and there were only two hours left in the school day, he said.
Students were dismissed at the normal time of 3:15 p.m., he said.
Only the power for the school was lost, said Candace Andrews, spokeswoman for the city of Richland. Homes around the school were not affected, she said.
A cable accidentally had been dug up, Andrews said. Fixing the problem will require minimal expense and was expected to be completed by about 5 p.m. Thursday, she said.