The building exterior doors are secured after business hours between 6:00 PM and 7:00 AM, Monday through Friday and all day during the weekends and holidays. The exterior building entrances and fire alarm system are monitored by Datawatch Systems. In the event of an after-hours emergency, call 911 and notify security at Two North Riverside Plaza, who maintains a 24 hour, 7 days a week security service. Security officers monitor tenants and visitors and make regular patrols of all building common areas and outdoor plaza.