Chicago's Office of Emergency Management and Communications held a three-day regional exercise to test and evaluate capabilities to respond to and mitigate large-scale incidents.

"Our intent is to conduct a low-probability, high-consequence exercise that builds on the previous workshops, meet the urban-area security requirements, and continue to develop and build local and regional response and mitigation partnerships," OEMC Director Ray Orozco said during a press conference.

The exercise was conducted on the site of two housing subdivisions that had been vacated for the upcoming O'Hare airport expansion program. Over the three-day period, participants simulated responding to IED detonations, using robots, and deploying SWAT and hazmat teams. The event also included mentoring programs for tactical-rescue and incident-management teams.

The exercise program was designed to offer realistic training scenarios and enhance the regional relationships, as well as measure response capabilities as they relate to the Department of Homeland Security guidelines. This exercise also kicked off DHS' new 36-month training plan.

Representatives from Chicago's fire and police departments, the Chicago Department of Aviation, Mutual Aid Box Alarm System, Northern Illinois Police Alarm System, Salvation Army, Red Cross, O'Hare Modernization Program, Cook County Office of Emergency Management and Homeland Security, and Chicago Transit Authority participated in the exercise.