The state legislature has hired a Minneapolis law firm to help in an investigation of the 35W bridge collapse, according to media reports.

The members of a joint bipartisan bridge investigation committee retained Minneapolis-based Gray Plant Mooty to serve as special counsel. The firm, which is being paid $500,000 to conduct its review, plans to issue a report of its finding in March.

Sen. Dick Cohen, DFL-St. Paul, told Minnesota Pulic Radio Wednesday that the investigation aims to uncover why the bridge collapsed, and also how to prevent future transportation problems.

In addition to this and the official investigation from the The National Transportation Safety Board, a private firm is also examining the state's bridge inspection program, and the Minnesota Office of the Legislative Auditor is scrutinizing MnDOT and its expenses. There are also several law firms that have launched similar investigations, MPR reported.

MnDOT is paying a Chicago-based firm that is working with the NTSB's probe $2 million to look into the collapse. Gov. Pawlenty has said that the firm would provide another set of eyes on the investigation.

However, the Star Tribune quoted state Sen. Dave Senjem, R-Rochester, who serves as Minority Leader, as saying the legislature's move would duplicate other investigations.