The first Laval overpass collapse six years earlier should have been a warning about Quebec's problematic infrastructure.

But many people forget that the de la Concorde overpass that gave way in 2006, killing five people, was not the first such tragedy of the decade.

A section of viaduct over Highway 15 had given way back in 2000, killing a man in the back seat of a car driving below. The overpass was still under construction, and a coroner's report later blamed shoddy workmanship. Meanwhile, across Quebec, some overpasses dating back to the 1960s continued to bear heavy daily loads. This despite the fact that some, including the one at de la Concorde and Highway 19 in Laval, had suffered potentially devastating erosion.

At 11:25 a.m. on Sept. 30, 2006, provincial police made a call to report concrete falling from de la Concorde. Traffic reporters were advised at 11:35, the transport department made a visual inspection just before noon and police reported a second fallen chunk at 12:33 p.m.

No one mentioned anything to motorists.

At 12:37, a 20-metre section of the structure collapsed onto the highway below, crushing several vehicles down to the level of rescuers' ankles. Among the dead was a pregnant woman.

The tragedy touched off anger across the province as well as concerns about bridges and overpasses that had been neglected by successive Quebec administrations.

Inquiry

Premier Jean Charest appointed one of his predecessors, Pierre Marc Johnson, to head up a public inquiry into the disaster. Johnson dropped a bombshell even before he tabled his report.

In the summer of 2007, he red-flagged 135 bridges and overpasses that needed to be demolished or urgently repaired.

His final report in October 2007 found that the 40-year-old de la Concorde overpass was poorly designed, with concrete that couldn't withstand freeze-thaw cycles or road salt.

The structure has since been demolished and rebuilt.

The collapse was also blamed on poor maintenance - a build-and-forget mentality that Johnson said has been the culture at Transport Quebec for far too long.

The report led the Charest administration to commit $500 million a year to overpass maintenance while implementing tougher quality controls.

Observers welcomed the government's decision to make investments that were decades late, though it took five deaths in 2006 - and one in 2000 - to make it happen.

And, until decades-old overpasses are replaced, many a motorist will glance upwards as they make their way along Quebec's highways.