Following a series of destructive thunderstorms that downed power lines and severely damaged electrical equipment, Commonwealth Edison (Chicago, Illinois) crews had restored service to more than 370,000 customers Friday evening and were continuing work to restore an additional 222,000 customers who remained without power. Despite a massive restoration effort, damage to ComEd's system was so severe that many of its customers were likely to be out of service for multiple days.

ComEd continues to assess the damage from the recent storms, which have been among the most powerful in the last few years. Broken poles, downed or snapped wires, and trees that uprooted and fell on equipment are among the challenges that crews are facing. Before power can be restored, crews must clear trees from wires, replace poles and transformers, and string miles of new wire. Downed trees, flooding, and traffic problems also are impeding crews' access to electrical equipment.

ComEd is using every resource at its disposal including additional reinforcement from other utilities. ComEd is deploying 720 crews into the field, working 16-hour shifts, including 192 tree-trimming crews and 230 crews from other utilities and ComEd's Philadelphia-based sister utility PECO. ComEd also has deployed hundreds of patrollers and damage assessment coordinators in the field to assess the full extent of the damage to the system.

"This series of storms has been the worst we've seen in the past 10 years," said ComEd Chairman and CEO Frank M. Clark. "As always, restoring power safely and quickly is our top priority. However, bringing all of our customers back to service will take several days. Our crews are performing incredibly well, but due to the destructive nature of these storms, we expect additional outages may occur as weakened trees and branches continue to come into contact with our power lines."

ComEd's emergency operations centers will remain open until all storm-related outages are restored and damage repaired. At the peak of the storms, more than 310,000 ComEd customers were without power, and over the course of the event, more than 500,000 customers have been affected.

"We greatly appreciate our customers' patience during this massive clean-up and restoration effort," Clark said. "We recognize that an outage of any duration is an inconvenience to our customers, and we are using every available resource to restore service as quickly as possible to our customers."