"We need to carefully review how we responded to this tragedy," the premier said at a news conference after touring the rescue site Wednesday and meeting with Elliot Lake Mayor Rick Hamilton.
"My undertaking to you all, and to all Ontarians, is that we will learn any lessons there are to be found here. Ontarians are committed to having in place, at all times, a world-class emergency response system."
McGuinty's briefing at the excavation site followed an emotional news conference earlier in the day, in which officials and the search and rescue head in Elliot Lake, Ont., described how they handled the emergency.
The victims have not been officially identified, but Lucie Aylwin was believed to have been trapped in the ruins of Algo Centre Mall. A second missing woman was identified as Dolores Parizolo.
Trauma to the two bodies has hampered efforts to identity the victims, but McGuinty said he offered condolences to the families of the two women.
"I've met with the families of Dolores and Lucie in their times of grief," the premier said. "I conveyed to those families that they've been in the thoughts and prayers of Ontarians since this tragedy struck your community."
Bill Neadles of Toronto's Heavy Urban Search and Rescue team said he doesn't believe any other bodies are trapped inside Algo Centre Mall, although rescuers still have to sift through a large pile of rubble.
But tough questions from the media and townspeople focused on the Monday setback, in which the rescue attempt was called off because of the threat posed by a precarious piece of concrete that Neadles said weighed "3,000 to 4,000 pounds."
Neadles described in dramatic detail how his team had to retreat after coming close to a person who was trapped but could not proceed because a massive piece of concrete threatened to crash down on his crew.
'We were in a precarious position'
"We had an individual who is now trapped in a very serious amount of heavy concrete," he said. "We were in a precarious position. I have 37 men to bring home to their families. I hope you understand what I had to do."
He went on to say he would make the same decision again.
Neadles described step by step how a major piece of equipment with a robotic arm was aided by two secondary pieces of equipment to slowly carve a path into the mall and methodically tear down parts of the building. Canine units helped recover the two bodies. Their names haven't been released.
"We were bringing all of the equipment we required," explained Neadles, who several times during the three-hour news conference defended his decision to stop the search on Monday.
"We got to 90 per cent and the roadblock came. We had to change plans. It weighs heavily on me to have to turn around and leave that individual in a position so helpless and defenceless."
Neadles and other officials called it a "miracle" that there were apparently only two deaths from the roof collapse in Elliot Lake, a former mining community of about 11,000 people that is 150 kilometres west of Sudbury.
"I saw the security video," said Neadles. "There were 26 people in that food court [just before the cave-in]."
The second body was found four hours after the first one. They were not far from one another.
Neadles said at the briefing, which began around 1:15 p.m. ET, that he expects the search should be completed in the next couple of hours.
Questions are swirling about the police investigation. Provincial police inspector Percy Jollymore said his department was assisting the Ministry of Labour and the Coroner's Office.
"Our Criminal Bureau of Investigation is fully engaged and our local criminal investigative unit is here."
There was no word about the mall's owner, Bob Nazarian. It was mentioned that his "representative" was on hand soon after the collapse and told officials that the mall owner was in agreement with anything they wanted to do for the rescue.
Before the intense overnight mall-dismantling efforts began, at least one person had been confirmed dead after the roof-top parking lot of the mall caved in Saturday afternoon, sending metal and concrete debris crashing through two floors of the building.
Town resident Catherine Timleck-Shaw told CBC News on Wednesday afternoon many people are still upset by the lack of transparency in the search.
"We were never kept informed. We had to find out everything from the news people and places on the internet," she said. "It's rather mindboggling that today we had nothing."
Another 12 people had remained unaccounted for, down from the 30 officials earlier estimated were missing. However, OPP Commissioner Chris Lewis said the number of people still missing hasn't been confirmed, although officials have good reason to believe they are not inside the mall.
Dan Hefkey, chief and assistant deputy minister at Emergency Management Ontario, had said early Wednesday morning that using the robotic arm on equipment from a Toronto construction firm, crews were able to move a massive section of an escalator and stairs that had prevented rescue workers from entering the mall.
The search for any survivors resumed late Tuesday after it had been halted Monday when it was believed there was a danger to people involved in rescue efforts, and there was public outcry and pressure from Ontario Premier Dalton McGuinty to resume the mission.
Rescuers 'devastated' by reaction to setback
At the afternoon news conference, Neadles' voice broke as he described how his team was "devastated" by a sense from Elliot Lake residents the crew was giving up prior to the heavy equipment arriving. He said it was his decision to take his team out because "beams were going to fail."
"These men are professional police officers, firefighters and emergency medical paramedics ... that you thought we were going to pack up and go home. That was devastating," said Neadles. "We would stay another four to five weeks if we had to."
The audience, made up of townspeople, began to clap as Neadles finished his remarks and stood up to give him and his team, who are all volunteers and unpaid for the work, the applause. A clearly choked up Neadles went silent.
Neadles collected himself and went on to say his team, all from downtown Toronto, were fuelled by the "community spirit" of the town: "We love you."
At the Wednesday mid-morning news conference, OPP Commissioner Chris Lewis defended the halt and the resumption of the search, saying that earlier in the efforts, workers were doing their best in a quick way to find any survivors.
Lewis said "this is a tragedy that I'm sure has affected everybody in this community." He added that based on earlier reports that the mall was old and on the verge of collapse for a long time, there will most likely be an investigation of some type.
"Between the OPP and the Ministry of Labour ... that will all be examined, and if there was something done wrong here, we'll deal with it.
Residents express frustration
Kalata said many residents who have been at the disaster site since Saturday have been frustrated and angry that they aren't hearing updates about the search efforts in a timely fashion.
One resident reacting to the news that a body was recovered said, "Where’s the rest of the people who are on the list” of persons believed to be missing?
The search and recovery efforts have involved teams from private interests and various levels of government, with Prime Minister Stephen Harper also pledging military help if needed.
But the added human and equipment arsenal only came after intense criticism from residents.
In an interview in the early afternoon Wednesday, Hefkey told CBC News that the search was suspended temporarily because two structural engineers assessed the situation, and determined it wasn't safe for either any possible survivors or search crew.
"The equipment the rescue team had at that time was insufficient," said Hefkey. "That's when the staff inspector asked for further assistance and that's where he reached out to me. That led to the bringing in of three immense cranes."
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