The Minnesota Legislature is bringing in some hired help for its ongoing investigation of MnDOT's role in the collapse of the Interstate 35W bridge.

The Minneapolis law firm of Gray Plant Mooty will earn up to $500,000 to investigate the transportation department's operations in the years leading up to the collapse, which killed 13 and injured nearly 100 others.

Exactly what brought down the span on August 1st will no doubt be a matter of engineering and physics. The National Transportation Safety Board is entrusted with that probe, but it won't necessarily answer State Senator Steve Murphy's top question.

"What can we do to make sure that this doesn't happen again?"

Murphy, the Red Wing Democrat who heads the Senate Transportation Committee, convinced the Rules Committee to authorize the Senate's half of the half million dollar contract. House leaders are expected to okay the other portion.

"Are tough questions going to be asked about who made what decisions and when?," Murphy asked, "Yes. They have to be."

The law firm will technically work for the joint committee formed to investigate the tragedy, and is expected to delve into MnDOT's inspection records and decision-making process.

Governor Pawlenty asserts the money would be best spent elsewhere.

"It seems like it's not a great use of public money to have a fourth investigation," Pawlenty told reporters Wednesday, "But that's up to the Legislature in their infinite wisdom."

The Pawlenty administration's already paying $2 million for it's own investigation of the collapse. MnDOT hired the firm Wiss, Janney, Elstner of Chicago to run a "parallel" probe of the NTSB's review. That may take a year or more to complete.

In the meantime, Legislative Auditor James Nobles is looking into MnDOT's handling of the 35W bridge leading up to the collapse. He expects to issue a report in February.

"Seems to me they want to have a redundant investigation," Pawlenty argued, "It may have a political tinge or a motive to it and that's not helpful."

That political question comes up for two reasons. Senator Murphy is a longtime critic of MnDOT and Governor Pawlenty's resistance to raising the state's fuel tax to address a huge backlog in transportation projects.

And Murphy argues the collapse should make it clearer than ever that the state needs to invest more in roads and bridges.

"What would you think?" Murphy remarked, "A bridge fell down, my God. If that's not clear indication that we need to do something differently I don't know what is!"

Murphy said that if the Auditor's reports and other official probes deliver the answers the joint committee's seeking, he'll be happy to call off the law firm's probe.

"We're committed to end our association with the outfit that we hired today, if those other people are finding what we need to make sure the public is safe."

"Right now it doesn't appear that we're going to get everything we need."

A report by the St Paul Pioneer Press Wednesday raised Gray Plant Mooty's connections to Democrats and DFL politicians, pointing out that US Senator Amy Klobuchar once worked there.

Murphy said, however, the committee picked a law firm with the least number of conflicts politically of the five interviewed for the job.

"Which outfit has the least baggage? We did due diligence and we all decided that GPM was the best in that regard."

Murphy said the current plan is to issue first of three formal reports in March.