L'EPIPHANIE -- The search for two missing quarry workers north of Montreal will continue throughout the evening Wednesday. While police say they’re still holding out hope of finding the workers alive, it is now mostly a recovery mission.

A constant stream of 60 to 80 workers pitching in to find a man and a woman, both operating heavy machinery, who were trapped in a landslide Tuesday at the Maskimo quarry in L'Epiphanie, about 25 kilometres north of the eastern tip of Montreal.

A transport truck rigged with heavy-duty search lights has cast enough light on the 100-metre-deep quarry to allow rescue workers to continue searching around the clock.

Rescue crews are carefully picking through mud, slush, and gravel because while they want to find the missing people, who they presume are most likely dead, they do not want to trigger another landslide.

“There's already an excavator that was left behind yesterday but we need to get a bucket to the bottom and attach it to the excavator,” said Bruno Marier of the Repentigny Fire Department.

The trucks, along with a crane, were working atop a large pile of mud, gravel and snow when the pile collapsed and slid into the quarry.

Crane operator Benoit Robert was able to scramble to safety, but the two trucks were swept off the side of the quarry's edge and buried in mud.

He was airlifted via a helicopter rescue and transported to hospital with minor injuries.

Repentigny police said the families of the missing man and woman gathered at the quarry Wednesday morning to watch the search operation.

Rescue crews were hindered Tuesday by the slippery terrain, and the Surete du Quebec had to resort to a helicopter to pick up the survivor, and to ferry rescue crews to the bottom of the quarry.

Those crews spent the day examining the terrain carefully with shovels, heat-sensing equipment and sniffer dogs before trying to dig out one of the trucks.

Before it got dark, they removed enough debris to look into the cab of one upside-down truck, but could not see any sign of anyone inside. .

Operations were called off at nightfall because rescue crews could no longer see, and they were worried about terrain.

On Wednesday rescue crews brought in a large crane in order to help excavate the debris that is burying the trucks at the bottom of the quarry.

That will be helped by switching out gear on an excavator that is parked in the bottom of the quarry.

"Our main goal is to try to bring some heavy equipment to the bottom of the quarry but there's no road to the bottom," said Marier. "We need to get a bucket down to the excavator so it can dig."

At 1:30 p.m. crews were still lowering equipment to the bottom of the quarry and had yet to make any significant progress on digging through the mud.

Crews standing on the mudslide were using sniffer dogs, probing cameras, and other equipment to try and locate the man and woman.

One of the canine squads had detected something near the top of the quarry, but more equipment was needed to determine what has been found.

Meanwhile CAQ leader Francois Legault visited the families of the missing workers.

“It's very tough for them, but I told them that we have to keep hope,” he said, adding that he was looking for answers.

“I want to make sure also that we have all the money, the equipment, the manpower that we need,” he said.

Legaut was assured that no effort was being spared in the search.

For the time being, the families are receiving psychological support and are still holding out hope their loved ones can be found alive.