Search-and-rescue crews were prepared to work through the night Tuesday to find any survivors trapped in a collapsed mall in Elliot Lake, Ont., using a massive robotic arm to clear away rubble.

The critical machinery required for the delicate operation arrived on site from Toronto. The 150-foot robotic arm was used to dismantle the façade of the Algo Centre Mall as some onlookers cheered on the renewed rescue effort.

Hundreds of residents have gathered to watch the controlled demolition.

Bill Neadles, spokesperson for the Heavy Urban Search and Rescue Team, said one of the chief concerns in the rescue efforts is an escalator that is still moving near where the victims are believed to be, adding to the instability of the remaining structure.

The arm will be used to stop the escalator—which had prevented rescue teams from entering the building-- and pull the device away from where the victims are thought to be, Neadles said.

Crews can then assess whether the building is stable enough for rescue teams and search dogs to enter.

The precise number of people missing and unaccounted for has fluctuated since the mall roof collapsed Saturday, but at a news conference on Tuesday, officials said 12 people are still missing.

So far, officials have only confirmed one death. Another 22 people were injured when a section of the two-storey mall's roof that served as a parking area suddenly collapsed.

Despite the arrival of the machinery, Neadles stressed that the likelihood of finding survivors at this point is increasingly slim.

No one has detected any signs of life since Monday morning and the prognosis is not positive, he said.

“Based on the information that we supplied him, our doctor was of the opinion that it was a very slim ability for a person to remain alive,” said Neadles.

Families angered by slow moving rescue efforts

Many families were frustrated by the seemingly slow pace of the rescue mission.

Rescue efforts were briefly put on hold Monday when officials said the site was too unstable and dangerous for the work to continue -- despite the belief that one person was still alive in the rubble.

Amongst those frustrated by the delay was Rejean Aylwin, who believes his daughter Lucie remains inside.

Lucie took a job at a lottery kiosk inside the mall and has not been seen since the collapse.

“They just gave up," Aylwin said on Monday. "It doesn't make sense. You can't give up. You've got to keep going until you find them."

Aylwin said he worked in a mine for over 30 years and the culture among miners is to never leave someone underground to perish.

Now the Aylwin family remains camped out across the street from the mall waiting for news of Lucie.

Gary Gendron, Lucie’s fiancée, called for the rescue workers to continue their work.

“As long as they don’t give up, I don’t mind. Don’t give up… you can’t give up on this,” he told CTV’s John Vennavally-Rao.

‘We hold all the people of Elliot Lake in our thoughts’

Premier Dalton McGuinty welcomed the news that the required machinery had arrived at the scene.

McGuinty released a statement on Tuesday night saying that all residents in Ontario will continue to hope for those still trapped in the mall.

“I know all Ontarians will join with me tonight in putting their faith in this rescue mission as, together, we continue to hope that those who are missing can be found and reunited with their loved ones,” said McGuinty.

Earlier Tuesday, Premier Dalton McGuinty said all parties involved are ready to enact "extraordinary measures to see if we might rescue those people that are trapped."

Speaking to reporters in Toronto, McGuinty said he had spoken with the local MPP, the mayor, as well as Prime Minister Stephen Harper -- and all agreed everything possible should be done to rescue those believed to still be trapped in the rubble.

"If that was your mom or your daughter or your brother and somebody came to you and said how far should we push, I think we would all say we need to go as far as we possibly can to rescue these individuals," McGuinty said.

McGuinty said the mall can be compared to a house of cards, where the wrong move could cause significant damage to the remaining structure.

"It might be that if you pull away at this wall in order to get access to somebody who's trapped in there, it may cause other things to move and other things to tumble and crumble," McGuinty said.

When asked why it had taken so long for the equipment to be dispatched, McGuinty said now is the time to focus on the rescue effort, not the "blame game."

McGuinty said Harper told him the federal government is ready to provide military personnel, expertise or equipment to the rescue effort -- if the province requests it.

The Prime Minister's Office issued a statement Tuesday thanking the first responders and saying the government's thoughts and prayers were with the families and the victims.

"Prime Minister Harper has offered the assistance of the federal government. We stand ready to assist as required," the statement said.

Earlier Tuesday, Ontario New Democrat Leader Andrea Horwath urged McGuinty to formally request the military's help in the rescue effort.

"When we look back on these days we must know that we did everything we could to save people's lives and ensured no soul was left behind. We must do everything we can," Horwath said in a statement.