When the steel in a bridge in Latchford gave way a decade ago, causing a section of the span to collapse, the town’s mayor says there were no warning signs.

“You presume that everything is being monitored to ensure it is safe,” George Lefebvre said.

Bridges are monitored and a visual inspection is required by law every two years.

But the province's auditor general flagged problems with the quality of those bridge inspections in a 2009 report. It noted bridge inspections take on average two to three hours to conduct.

In fact, data from 2012 inspection reports in Sudbury shows 14 bridges were checked in a single day.

David Shelsted, the director of roads for the city of Sudbury, said bridges vary in complexity — and it's up to the professional engineers who conduct the inspections to take the time they need.

“That's their profession on the line to make sure that they have done this to the intent of the inspection manual and that they are providing good service to the city,” he said.

Shelsted said the city is happy with the bridge assessments in 2012 and plans to use the same firm for the next round of mandatory inspections next year.

What about culverts?

Bridge inspections may be mandated by the province, but some critics charge that culverts continue to be a hidden danger.

Gerry Mulhern has spent years examining what is under Ontario roads.

He is the executive director for with the Ontario Concrete Pipe Association and has been pushing for a database that would help the Ministry of Transportation monitor the condition of all culverts, not just those large enough to be classified as a bridge.

“This is first and foremost a public safety issue,” Mulhern said.

“I am convinced that it is a statistical certainty that culverts will continue to fail under MTO highways and municipal highways across Ontario.”

The Ministry of Transportation was not able to provide information on the status of the culvert database, but said it now requires more detailed information from highway contractors about the condition of culverts, so it can more effectively fix and replace them.

The ministry provided CBC News with the following statement:

Area Maintenance Contractors are required to conduct a condition assessment of all centreline non-structural culverts in their contract area annually. Non-structural culverts are defined as those with a span less than three metres.

The inspection of structural culverts is managed by the ministry's regional structural section. The Area Maintenance Contractor can be assessed a non-conformance and an associated financial penalty for failing to provide the information outlined in the contract with respect to the condition of non-structural culverts within the contract limits.

The ministry's Area Maintenance Contracts have always required the contractor to inspect non-structural centreline culverts. The current Area Maintenance Contracts do require more detailed information about the condition of non-structural centrelines so that the ministry can more effectively identify culvert conditions and prioritize culvert replacements.

For more on the condition of bridges and culverts in Sudbury, stay tuned to CBC's Morning North radio program this week for our special coverage called Sudbury's Big Fix.

You can also find an interactive map on our website.