Power has been restored to nearly all of the 20,000-plus homes and businesses in Parma and Parma Heights that were without it Thursday afternoon.
In Parma more than 16,000 customers were without power, and in Parma Heights more than 6,000 customers were without power.
FirstEnergy spokesman Mark Durbin blamed the loss of power on an "issue with a substation" but could not be more specific.
There were also smaller outages in Middleburg Heights, North Royalton, Brook Park and Berea. It was not clear if they were related to the Parma-Parma Heights outages.