Multiple agencies brought together to prepare for triage, processing of patients.
Complete with realistic looking head wounds and burns, officials and volunteers conducted the first evacuation drill from the city's central business district in four years.
"The purpose of this exercise is to enhance the public and private sector relationships in order to coordinate and strengthen response capabilities," explained OEMC's Executive Director, Jose A. Santiago.
The drill was put together by Chicago's Office of Emergency Management and Communications and included roughly 500 volunteers from AON and Blue Cross/Blue Shield.
The drill included the evacuation of the two buildings, sites of "major explosions," screen the victims and assign them to triage areas for care.
Unharmed evacuees were bussed to an intake center for processing and ID checks. They were shown a streamlined system for family members to locate their loved ones in the event of a real tragedy.
"As realistic as you can make it, that's important," said the Chicago Fire Department's Mark Nielsen.
Firefighters said one of the biggest benefits is practicing working with other agencies like the police, the county emergency responders, the Red Cross and Salvation Army.
"The more we can actually practice and meet everybody, and we all know each others' capabilities, the better we are going to be in a real-life response," said Dan Ellis with the Chicago Fire Department.