CHICAGO (AP) _ Six people were killed Friday in a fire that trapped workers in smoke-filled stairways and hallways of a high-rise office building in the heart of downtown, officials said.

``The people that have passed away appeared to be for the most part from one area in one stairwell,'' said Fire Superintendent James Joyce.

Some of the victims inside the 35-story Cook County administration building were not found until after the fire was brought under control. Firefighters were conducting a floor-by-floor search when some of those trapped called 911 on their cellular phones.