Chicago's ComEd today mobilized to respond to system outages caused by the worst storm in a decade and unleashed a full contingent of crews to repair downed power lines and other damaged equipment. Due to the devastation, ComEd is expecting restoration efforts to take several days. ComEd is still evaluating impacts on the system and will have more detailed restoration information later today.

At today's storm peak, more than 765,000 customers in were affected; approximately 178,000 customers have been restored since the start of the storm.

ComEd currently has approximately 480 crews in the field and is requesting assistance from all available resources, including contractor crews and assistance of crews from neighboring states. It also has enlisted additional staffing to manage the large volume of calls experienced by the customer call center.

"We recognize that power outages disrupt the lives and businesses of our customers," said Anne Pramaggiore, president and chief operating officer, ComEd. "ComEd crews are working hard to restore service to customers affected by the storm as quickly and safely as possible."

The powerful storm began moving through the ComEd service territory around 6:00 a.m. and departed by 9:30 a.m. Most damaging to the ComEd system was intense lightning, with high winds as a factor in causing extensive tree damage and bringing down power lines. The resulting outages are more difficult and time consuming to restore as they involve attention to more individualized equipment.

The largest number of outages is located in the company's northern and western regions. ComEd is working with municipal officials and businesses to provide ongoing updates to them regarding restoration efforts.

ComEd's restoration process begins with damage assessment, this process enables the company to determine hardest hit areas and factors into restoration times. The company then prioritizes outage restoration to ensure public safety first such as police and fire, then hospitals and other critical customers. Next, ComEd restores feeders, which allows us to return power to large numbers of customers at one time, followed by smaller service restorations and individual outages.