Armour, E. H. Harriman and their heirs. Conflict with the subway Plans for passenger subway service in Chicago date back to the turn of the 20th century, and the original permits to dig the freight tunnels allowed for future cut-and-cover subway development above the tunnels. In the 1930s, when the Chicago Rapid Transit Company and the city finalized the design of the State Street and Dearborn Street subways, plans called for the tunnels to be dug through the blue clay along the line originally followed by the freight tunnels. Excavation debris from the new subway tunnels was hauled away by the Chicago Tunnel Company as the subway replaced the freight tunnels along their route. Company failure The Chicago Tunnel Company went bankrupt and applied for voluntary reorganization in 1956. The tunnel company attempted to sever itself from the bankrupt holding company, claiming it could operate at a profit, but by 1959, the tunnel asked for abandonment permission. The Interstate Commerce Commission consented to abandonment that July, and the tunnel assets were sold at auction for $64,000 in October. Tunnel flooding In late 1991 near the Kinzie Street Bridge, a new set of pilings (collectively known as a "dolphin") were driven into the riverbed to prevent barges from bumping into the bridge. As the pillars were installed, a miscalculation was made that caused severe damage to the tunnel directly below the river. The risk of flooding was well understood by George W. Jackson, the chief engineer who built the tunnel system. In 1909, Jackson received a patent on a portable bulkhead that could be used to seal off flooded tunnel sections. The tunnel developers were also concerned by the flooding risk posed by firefighting efforts in buildings connected to the tunnels. Should a building catch fire, immense quantities of water could pour into the tunnels through elevator shafts and basement connections. To deal with this risk, watertight fire doors were fitted into all building connections. Small leaks in the tunnels under the Chicago River had become commonplace by 1913; to deal with them, the tunnel company drilled holes in the tunnel wall and pumped grout at high pressure into the soil outside the tunnel in the vicinity of the leak. The 1992 flood was not the first time that a contractor's action threatened to flood Chicago by puncturing the tunnel. In 1959, an excavation punctured the tunnel, leading to a dramatic