Police were called to the building around noon after an unattended bag was found in the concourse area. Bomb and arson was called, but only the lower levels were evacuated.
The scene was secured about 2.5 hours later and employees were allowed to reenter the building.
Trains on the CTA's Blue, Brown, Green Orange, Purple and Pink lines were bypassing the CTA's Clark/Lake station, but have since resumed normal service.
