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In page Chicago flood:

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Workers attempted to plug the hole, by then about 20 feet (6.1 m) wide, with 65 truckloads of rocks, cement and old mattresses.[1] In an attempt to slow the leak, the level of the Chicago River was lowered by opening the locks downstream of Chicago,[citation needed] and the freight tunnels were drained into the Chicago Deep Tunnel system. The leak was eventually stopped by placing a specialized concrete mixture supplied by Material Service Corporation (MSC) and placed by Kenny Construction. The concrete was designed by Brian Rice of MSC and was to set up so quickly that the concrete delivery trucks were provided police escorts. The concrete was placed into drilled shafts into the flooded tunnel near Kinzie Street and formed emergency plugs.