Just before Chicago’s WTTW was to go on the air Wednesday with their newscast “Chicago Tonight” all employees were ordered to leave the building.

Robert Feder reports that a threat called into the station had Chicago police surrounding the studio and telling people to get out.

A company rep confirmed: “WTTW received a phone threat on October 27. The police were notified, and as of now, there has been no incident.” police detectives are investigating.