Remembering the 'Great Chicago Flood' 30 years later

Wednesday marked 30 years since the "Great Chicago Flood" of 1992.

On April 13, 1992, an underground tunnel wall failed, causing dozens of office building basements to flood and forcing the evacuation of thousands of downtown office workers. What some people may not realize is that this was a disaster that could've easily been avoided.

"This is one of these great Chicago stories," said John Russick with the Chicago History Museum.

As early as three months before the flood itself, utility crews found several feet of mud, clay and water already having leaked into Chicago's underground network of tunnels — tunnels once used for coal transport, package delivery, and utility lines to downtown office buildings.

"This was a serious problem that required an immediate repair and it should've been expedited," then-Mayor Richard M. Daley said in the days following the flood. "This morning, I requested and received the resignation of acting transportation commissioner John LaPlante. This problem was brought to his attention, he failed to act, resulting in a major problem that could have been avoided."

It wasn't until hundreds of millions of gallons of the Chicago River had flooded the tunnel system that crews discovered the source of the breach.

"It takes a while before people realize there's this breach around the Kinzie Street Bridge," Russick said. "There's a whirlpool there."


Several pilings installed there put too much pressure below, creating a car-sized hole in the tunnel wall, flooding the system and forcing the evacuation of thousands.

"Most, if not all of those buildings have done an extensive rethinking of the way their buildings are connected to this independent tunnel system," said Russick.

If you want to learn more about the Great Chicago Flood, the Chicago History Museum has a vast collection of images, along with one of the actual dive suits used in the frantic response.