The Minnesota Department of Transportation hired — but decided not to use — an engineering consultant to help look for flaws in the Interstate 35W bridge just three months before the span collapsed, a newspaper reported Wednesday.

The Star Tribune said transportation department staffers used visual and ultrasonic methods in May to go over just over half of one critical section of the bridge and then suspended the inspection, planning to resume it this fall after a resurfacing job on the bridge was finished.

The bridge collapsed Aug. 1, killing 13 people and injuring more than 100.

The newspaper said the unfinished inspection raised questions about why transportation officials didn't complete the inspection in the spring or use its consultant after awarding it a contract for that purpose.

"The inspectors who were going through it did not have need for assistance," state chief bridge engineer Dan Dorgan told the newspaper. "I talked to the inspectors sometime after May. Pretty brief. 'Did you find any problems?' And the answer was no."

Ronald Low, a spokesman for the consultant, URS Corp., told the newspaper the company would not comment and referred all questions to state transportation officials.

The newspaper also reported that the initial focus of the special inspection was going to be on the south end of the bridge, the part believed to have collapsed first, but state inspectors instead started on the north end. Officials said the switch was made for logistical convenience.

"The bridge inspection is one of the many things that we're looking at as part of this investigation," said Terry Williams, a spokesman for the National Transportation Safety Board, which is leading the main investigation into the collapse. "We're still in the early stages."