Problems with shifting electricity loads at the Desplaines Avenue Commonwealth Edison sub station in Forest Park caused up to a three hour blackout for 15,390 near west suburban homes early Christmas morning.. Power went out for most of Forest Park, as well as portions of Oak Park, River Forest, Berwyn, Maywood and North Riverside at 1 a.m. ComEd crews managed to restore power to some 1,700 customers by 2:40 a.m., and all homes were back on line by 4 a.m.

Following the incident, ComEd spokesman Luis Diaz said that crews were performing scheduled work on the substation at 769 Desplaines Ave. when they encountered difficulty switching an electrical load.

On Tuesday morning, ComEd spokesperson Judy Rader said that the precise cause of the incident was still under investigation.

Forest Park police were kept busy opening up stop signs at traffic controlled intersections. Around 1:30 a.m. a Forest Park police officer let down the stop sign at Madison Street and Jackson Boulevard. He knew few details about the outage at that time, except that all the traffic and street lights were dark.

While Forest Park was pitch dark from south of Roosevelt Road to north of Madison Street, Oak Park blazed with lights by comparison across Harlem Avenue. But police there were kept busy with traffic control at major intersections along Harlem Avenue.

Looking west on Roosevelt from Desplaines one could see traffic lights west of First Avenue. The lights along the Eisenhower Expressway were out between First and Harlem. The intersection of Desplaines and the Eisenhower, near where the substation is located, was eerily dark, with only the lights of cars passing underneath offering illumination between the passing overhead of CTA Blue Line trains. Along Roosevelt Road, the yellow glow of exterior lights from parked semi-trailer trucks offered the only illumination around.