Fox 9, Twin Cities investigators have discovered a lawsuit that was filed against MnDOT, then known as the Highway Department, by the contractor of the original I-35W bridge over 40 years ago.

Industrial Construction claimed in the lawsuit that the bridge could not be built the way the state wanted. Engineers discovered an unexpected geology--underneath the bridge was 25 ft of clay, rock and granite, including small granite boulders and limestone float, which made it impossible to drill any deeper. The lawsuit said that the contractor had been misled about the geology and therefore the difficulty of the project.
The other contractor involved with the construction, HurCon, also had expressed concern about the project. It told MnDOT that one portion of the bridge, Pier 6, could not be built as planned. It wanted to blast the site, but MnDOT refused. HurCon then backed out of the project altogether.
The top decking right above Pier 6, located at the south end of the bridge, shifted 80 ft to the east as the bridge collapsed this past August. The south end was also the location of the construction work that occurred as the bridge collapsed. Much of the weight of the construction bore down on Pier 6.

MnDot said it was unaware of the old lawsuit until last month.