Chicago Tribune:
MINNEAPOLIS - The highway bridge that collapsed into the Mississippi River on Wednesday was rated as "structurally deficient" two years ago and possibly in need of replacement.

That rating was contained in the U.S. Department of Transportation's National Bridge Inventory database.

Jeanne Aamodt, a spokeswoman for the Minnesota Department of Transportation, said the department was aware of the 2005 assessment of the bridge. "We've seen it, and we are very familiar with it," she said.

Aamodt said the department plans its bridge repairs using information from the Bridge Inventory database.

Many other bridges nationwide carry the same designation that the I-35W bridge received, Aamodt said.

Aamodt declined to say what the agency was going to do to address the deficiencies found in 2005 and referred further questions to Dan Dorgan, state bridge engineer and director of the bridge office. Dorgan wasn't available for comment.

The deficiency rating is derived from a complex formula that evaluates many factors and condenses them into an overall score. A score of 80 percent or less indicates some rehabilitation may be needed; a 50 percent score or less indicates replacement may be in order.

The I-35W bridge was rated at 50 percent. The rating data was provided to the Star Tribune by the National Institute of Computer Assisted Reporting.

The inventory data also summarize the bridge's status as "structurally deficient." Bridge components are ranked on a scale of 0 to 9, with 0 being "failed" and 9 being "excellent."

In 2005, the bridge's superstructure -- meaning the physical conditions of all structural members -- was rated at 4, records show. The bridge's deck was rated 5, and the substructure, comprised of the piers, abutments, footings and other components, was rated 6.

In 2001, a research report on the bridge had found that it was unlikely to experience any fatigue cracking in the trusses supporting its deck. The paper, prepared by the University of Minnesota's Center for Information Studies, evaluated both the main trusses and the floor truss of the bridge.

The report by the late Robert J. Dexter and others, concluded that the bridge's deck "has not experienced fatigue cracking, but it has many poor fatigue details on the main truss and floor truss system."