Wind gusts and precipitation brought down power lines and left thousands without power throughout Illinois in the season's first winter storm.
More than 100,000 people were left without power, a Commonwealth Edison spokesperson said.
By Friday afternoon, that number had dwindled to about 1,000 customers, mostly in the western region of Illinois, including Rockford and the Quad Cities.
The utility said it hoped to have service restored to everyone by the evening hours.
ComEd prepared for power outages and significant damage to its system, put out additional crews and equipment and asked other utilities to be at the ready to assist.
ComEd Vice President Terence Donnelly predicted the storm to be "especially damaging" to the company's power system because of the combination of wind, snow and ice.
Customers can report outages by calling 1-800 EDISON1 or visiting ComEd.com.