The water tank at the Brewster building was one of fewer than 180 tanks left in the city that serve as a reminder of resilience after the Great Chicago Fire in 1871, the Chicago Tribune said Wednesday.
The wooden and steel tanks were built to hold water primarily as a fire suppression measure, but some were and still are used to supply water to residents living in multistory buildings.
Fire Department spokesman Larry Langford said the city's Department of Buildings would lead the investigation into what caused the Brewster water tank to collapse.
"Was any maintenance done recently? Did anyone check the mounts recently? Obviously the wind didn't blow it over," he said.
There's a historical preservation effort to save what few water tanks remain in Chicago -- there were 373 in the early 1990s -- and as such, those still in place are inspected every five years. The Brewster was cited in 2010 for code violations, including misplaced steel bands around the tank, the Tribune reported.
One woman was critically injured in the accident and she and the man she was with were taken to Advocate Illinois Masonic Medical Center. A third victim, a woman, was taken to St. Joseph's Hospital in fair to serious condition, the newspaper said.