The state is suing its main consultant on the Interstate 35W bridge, alleging it failed to carefully analyze its condition before its disastrous collapse that killed 13 people and injured 145 others two years ago.

The state’s lawsuit contends URS Corp. of San Francisco, Calif., failed in its responsibilities to inspect, analyze and evaluate the bridge. The lawsuit notes that URS held three contracts with the state to inspect the bridge and suggest modifications and that the company assured the state of its expertise in assessing the need for repairs.

URS spokesman Ronald Low says the company intends to “vigorously defend” itself.

URS noted the National Transportation Safety Board’s findings into the cause of the collapse pointed to both the bridge’s original flawed design and the spacing of materials on the bridge as part of a construction project.