The Chicago Flood began on April 13, 1992 when a hole was punched in the bottom of the Chicago River causing a leak which eventually flooded much of the Loop. Workers on the Chicago River were putting in new pilings when one of them punched a car-sized hole through the bottom of the river into an abandoned railway tunnel used in the early twentieth century to transport coal and goods. Workers attempted to plug the hole with rocks and mattresses to no avail.

The water flooded into the basements of several Loop office buildings and retail stores and an underground shopping district. The city quickly evacuated the Loop and financial district in fear that electrical wires could short out. Trading at both the Chicago Board of Trade and the Chicago Mercantile Exchange ended in mid-morning as water seeped into their basements.

It took three days before the flood was cleaned up enough to allow business to begin to resume and cost the city an estimated 1.95 billion dollars. The Army Corps of Engineers flew up mine divers from Kentucky to work on sealing the hole.