Officials suspect a chunk of concrete that fell from an overpass onto Highway 25 in Montreal on Monday morning was dislodged by vibration from a passing truck.
Transport Quebec officials closed the south part of the highway after a 30-centimetre piece fell off of the Hochelaga overpass.
Officials said the concrete that came loose was a gutter, a piece used to cover up the steel cables that hold the overpass together, so it's loss doesn't affect the bridge's structural integrity.
The Hochelaga overpass has had major inspections for the past three or four years as it awaits a complete re-construction this summer.
"Sixteen-million dollars to reconstruct the whole structure will be done this summer," said Transport Quebec's Alexandre Debs told CTV Montreal.
The engineer said that he was surprised to hear that the gutter had fallen, but he's confident that the bridge is safe.
He explained that Transport Quebec is re-constructing the bridge in a few weeks.
"It was planned much before what happened today," he explained.
This wasn't the only concrete to fall from Montreal's transport structures in the last few days.
On Sunday, a square chunk about a half-a-metre long came down from the roof of the Louis-H. Lafontaine tunnel.
A witness, who watched the piece plummet to the ground about 100 metres from his car, said that it immediately reminded him of the Concorde overpass.
Five people were killed in Laval, Que. when the structure collapsed last year.
Jules Bonin, an inspector for Transport Quebec, visited the Concorde overpass on September 30 and noticed material crumbling off the bridge 45 minutes before it rumbled and fell onto motorists.
Bonin, testifying at the public inquiry into the tragedy, said seeing the several chunks of concrete that had fallen from the Highway 19 overpass didn't prompt him to take action.
"I didn't consider it extremely urgent," he said. "I never thought it was going to fall."
With a report from CTV Montreal's Tanya Krywiak
