The engineer who designed Laval's de la Concorde overpass told the inquiry investigating its collapse Wednesday that his plans were not properly followed.

Gilles Dupaul was the senior engineer responsible for designing the Laval overpass when it was built more than 35 years ago.

Gilles Dupaul told the inquiry that builders did not stick to his plans.
(CBC News)

Although the 78-year-old admitted he had never visited the site during its construction, he said he realized the steel reinforcement bars were not in the right place after reviewing photos of the collapse.

Dupaul said in some places the steel bars, used to reinforce concrete, seemed to be too short and there were too few of them.

A supervisor should have been on site to inspect the placement of the steel bars before the concrete was poured, he said.

According to contracts released by the commission of inquiry, a company called Acier d'armature de Montreal was responsible for installing the bars.

Although the company is now defunct, its former president told Radio-Canada he believes he contracted out the installation to another company, Desrochers Steel, which is also defunct.

The inquiry's head prosecutor has confirmed the commission is still trying to establish which company installed the steel bars.

The inquiry into the September collapse that killed five people and injured six others got underway in Montreal earlier this month.