The Knoxville Fire Department responded to a report of a carbon monoxide detector going off at 111 East Main Street at 3:30 pm Wednesday. Firefighters evacuated One Eleven Public House restaurant and neighboring buildings as a  precaution due to moderate carbon monoxide levels. Alliant arrived on the scene and investigated, It was determined that the cause of the issue was a vent from one of the furnace systems that was exhausting into the roofline and coming back into the building. All buildings were ventilated and once CO levels reached zero tenants were able to return to their units. The Knoxville Fire Department was assisted by The Knoxville Police Department, Marion County Emergency Management, and Alliant.