NORRISTOWN, Pa. (CBS) – Officials say a private contractor that was digging underground hit electrical equipment and caused a fire in Montgomery County Tuesday morning.

The situation began at about 8:45 a.m. at W. Main Street and Cherry Street in the downtown Norristown area.

Officials said employees with the private contractor were digging in the ground when they accidentally hit electrical equipment in the ground, which prompted a fire at a Dunkin’ Donuts shop.

An employee at the Dunkin’ Donuts was injured when she tried to extinguish the fire. The unidentified employee was taken to the hospital for treatment of burns to her hands.

PECO officials say approximately 25 business on the block will be without power for at least 24 hours while repairs are made.