A highway overpass in Quebec was so weak when it crumbled last June, killing one, that the wind could have blown it over, according to a report.

An engineering report on the incident, tabled by Quebec Transport Minister Guy Chevrette, concluded that anything from high winds to vibrations from passing traffic could have caused the overpass' eight concrete supports to cave in.

A structural system should have been installed to prevent the shifting of supports during construction, the study stated.

The accident killed one and injured two others.

The report stopped short of placing blame, however.

Beaver Asphalt, the City of Laval and a supervising company were all involved in the overpass' construction. While determining who was ultimately responsible will be up to the coroner and judicial authorities, politicians are already assigning blame.

Thomas Mulcair, a member of the Liberal Opposition in Quebec, said the Bloc Quebecois government helped Beaver Asphalt get the contract when it contacted its main creditor, the National Bank.

Premier Lucien Bouchard has denied the charge.

Highway 15 is the busiest route between Laval and Montreal. About 150,000 commuters use the highway everyday.

Police said the death toll could have been much higher if some motorists hadn't swerved to avoid the crumbling roadway.