 The hospital was expanded in 1869, with its address on Prairie Avenue, a street just east of Calumet and running parallel to it, which proved timely when the Great Chicago Fire happened in 1871, located outside of the burned area but close enough to help fire victims.In 1968, after planning a new and modern facility since the 1950s, Mercy Hospital opened in its present location on South Michigan Avenue, just west of its former location.The site extends from 25th to 26th Streets, and from Michigan Avenue east to Martin Luther King Drive.