Built in 1894, the Rock Island Swing Bridge was the longest swing span bridge in the world at that time and is claimed to be the only remaining swing bridge in the US that was uniquely constructed to carry trains on an upper level deck and passenger traffic on the lower level deck.
Two weeks ago a section of the eastern portion of the swing bridge, around 60m in length, collapsed.
The bridge had been closed to all use since 1999, but Dakota and Washington County officials have been considering whether the bridge could be reused as a pedestrian walkway or whether it should be removed.
Now it is likely that the plans to remove the structure will be accelearated, according to Dakota county officials.
"The bridge is property of the State of Minnesota," said Dakota County’s transportation director Mark Krebsbach. "Decisions on how to proceed will ultimately be made by the State. This may accelerate planning for disposition of the bridge."
Representatives from Minnesota Department of Transport, Washington County and Dakota County have concluded that the collapse was due to severe corrosion at the connection between the pier columns and the primary girders supporting the roadway.
"The structural condition of the bridge is very poor. This lead to the bridge being closed to traffic in 1999," said Krebsbach. "The structure has continued to deteriorate since that time prompting the planning for potential removal. However, there were no clear indications of imminent failure."