President Barack Obama and first lady Michelle Obama were in the neighborhood to tape the Oprah show, but the Harpo studio was not affected by the outage.
ComEd says the boundaries of the power outage are Ohio south to Congress and Canal west to Racine. The fire department says not all buildings within those boundaries are affected.
Firefighters had to assist people stuck in an elevator at 900 W. Jackson.
As of about 12:30 p.m., ComEd did not have an estimated time for restoration of power.