The harshness of Minnesota winters also came into play. Minutes show that MnDOT officials saw a benefit to immediately reinforcing the bridge because it could choose the exact time, conditions and method of work.
"If we wait until an inspection finds a crack before we reinforce the steel, then random chance and weather will dictate ... This will negatively impact cost, quality and safety," according to minutes of the July 2006 meeting.
MnDOT officials didn't dispute the accuracy of the minutes. But they pointed out that the risk-benefit analysis was undertaken before URS made assurances in January 2007 that cracks could be found and neutralized before they reached a dangerous length. URS has declined to answer Star Tribune questions since issuing a brief statement in the days after the bridge collapse.
And in interviews, both Dorgan and Peterson scoffed at the notion that a $1.5 million expense to fix one of the state's busiest bridges was an issue in a department that annually spends hundreds of millions. Overall, MnDOT spends about $2 billion a year.
A month after the "investment strategy" meeting, Dorgan wrote a memo in response to the first draft of URS' written crack study of the I-35W bridge. Dorgan didn't want the consultant to mince words when it came to explaining what would happen if a fracture-critical beam in the superstructure failed.
"If the conclusion is the instability would likely lead to the collapse of the bridge, that should be stated clearly," Dorgan wrote.
It was part of the extensive give-and-take that went on between the consultant and MnDOT ever since URS received the contract in July 2004 to identify the structural members of the main spans of the bridge that were most susceptible to cracking.
For instance, in September 2006, three months after URS issued the first draft of its final report, MnDOT asked the consultant to verify the toughness of the steel used to build the bridge. The issue of toughness was raised because it affects how quickly cracks could spread and the time inspectors would have to find and react to them, according to documents.
But Dorgan said MnDOT never got an answer before making its decision to proceed with the inspection option.
According to records and MnDOT's timeline, here's how the agency turned, as Dorgan said, "180 degrees" to embrace inspections over reinforcements:
June 2006 URS recommends reinforcing 52 truss members most susceptible to cracking.
Mid-October 2006 The Bridge Office requests money for reinforcing and the project is funded with $1.5 million.
Late November 2006 URS is told to make plans for a contract letting in October 2007.
Dec. 19, 2006 URS informs MnDOT that ultrasonic inspections are an alternative to installing reinforcing plates. URS sends a draft of revised recommendations to MnDOT. The three options are to reinforce 52 beams, inspect the beams with ultrasonic equipment or a combination of reinforcing 24 beams and inspecting the other 28.
Jan. 17, 2007 The turning point occurs during a conference call. Dorgan and staff opt for inspection only. He says the decision is based on URS assurances that inspectors can detect and isolate cracks before they reach a dangerous length.
Jan. 18, 2007 Gary Peterson tells MnDOT's Metro Division that the plate-installation project will be delayed until at least fiscal year 2008-2009.
May 2007 Inspections of critical beams begin on half of the designated beams. Inspections were halted when concrete repairs began and were to resume in the fall.