Police have a list of people who remain unaccounted for in the wake of Saturday's tragic events, and by late Sunday night it still contained nine names.
But Ontario Provincial Police Insp. Percy Jollymore insisted that number was fluctuating as some of those reported missing had been located and others — who hadn't been heard from — were added to the list.
"The problem with this is there's no precise science, we don't know who was in the mall when it collapsed," said Jollymore. "We won't stop until the list has been satisfied."
Meanwhile, a rescue official said at least two people were trapped in the rubble as crews worked around the clock to stabilize the scene.
Officials suspect one of those imprisoned "could be a casualty," but they said it would take until early Monday morning before the structure was deemed safe enough for search and rescue teams to go in.
Provincial police said images of the partially collapsed roof at the Algo Centre Mall, which served as a parking lot, showed a hand and a foot in the dusty debris.
"We have obtained some visual information relating to a visual of a hand and a foot which is our grounds for the suspected casualty in this case, we cannot confirm the identity," said Jollymore.
"The location is such that we cannot approach it at this time."
Officials also said they heard some taps coming from behind fallen slabs of concrete and metal.
"Some of our search members this morning heard a couple of taps," said Bill Needles, a spokesman from the Heavy Urban Search and Rescue team which travelled from Toronto.
"They called for a quick silence on the site and there was a couple more taps. That was an indication to us that we were dealing with a rescue," he said.
"We then turned our whole efforts towards trying to locate this individual. There was no verbal, there was no sight, we have no idea if it's male, female, what age, it was just a tap."
Needles said crews drilled through a wall in an attempt to locate the victim but weren't able to find anyone. At that point crews decided the site was too unstable to send in rescue workers.
The operation is still a rescue mission, though, and officials said they were still hoping to find people alive.
"We're believing that they're still there and still alive," Needles said.
The roof of the mall came crashing down through two floors just before 2:30 p.m. on Saturday. The collapse left a gaping hole about 12 metres by 24 metres, downed hydro lines and it triggered a gas leak.
Two kiosks selling lottery tickets, cigarettes and magazines were located in the area where the roof caved in and were open before the incident, eyewitnesses said.
By Saturday evening, hope mingled with frustration in the close-knit community as residents waited anxiously for news.
"There's a fair amount missing," said Heather Richer, who owns a restaurant in the mall and was at work when the collapse occurred.
"I'm hoping everyone's found, but I'm giving up hope on whether they're going to find them alive."
Richer, who was particularly concerned about an acquaintance who was unaccounted for, described Saturday's thunderous collapse as a nightmare.
"It was almost like a little mini earthquake, like a big bang, and then gone," she said. "There was nothing there. Everything started to cave in, water was pouring out of the pipes."
The two-storey centre, which was built in the early 80s, underwent a structural study in May and received a passing grade, said a source with Eastwood Mall Inc., which owns the mall.
Work was being done on the roof before the collapse to prevent leaks, but no "substantial renovations" were underway, the source said.
Work to re-seal the surface of the roof was, however, planned for the near future.
As emergency crews continued to scrutinize the scene on Sunday, some irate residents in the city, which in recent years has become a popular retirement destination, said the mall, while a bustling community hub, was an older building much in need of repairs.
"The mall's always had leaks (and) roof damage," said Jean-Marc Hayward, who was in the mall at the time of the collapse.
"There's a spot near the food court where there (was) a hole in the ceiling and you could see the beams and they're all rusted."
Hayward, who heard and felt a loud rumble moments before the roof crumbled, said the ceiling of the mall always dripped when it rained.
"I used to say, 'One of these days, a car's going to come through there'... it finally gave way, I guess," he said. "I'm still shaken up about it."
The owners of the mall travelled to Elliot Lake soon after the incident to offer support to the community.
"To those who have been injured, to those families of missing individuals, we offer our deepest sympathies," said Levon Nazarian, whose father, Richard Nazarian, owns the mall.
"We are, and will be co-operating with the authorities to provide them with any helpful resources that are at our disposal."
Police continued to urge anyone worried about missing loved ones to check in at an information centre where police are tracking those who are unaccounted for. Vicars and crisis councillors were on hand.
Concern for the community poured in Sunday, with political leaders pledging their support.
Premier Dalton McGuinty said he was in touch with Elliot Lake's mayor and thanked emergency crews in the city for their efforts.
"As we anxiously wait to learn more about anyone thought to be missing in Elliot Lake, our thoughts and prayers are with their families, and also with those who have been injured and indeed with the entire community," McGuinty said in a statement.
"During a crisis like this, I am reminded of the strength and resilience of Northern Ontarians, and how by pulling together with our friends, families and neighbours, we can get through these difficult times."
Ontario NDP Leader Andrea Horwath said she was inspired to see the community of roughly 11,000 pull together during the crisis.
"There will be time soon to examine what happened and why, but right now our priority has to be protecting people's lives and health and ensuring the immediate disaster relief this community needs," she said in a statement.
The mall houses a grocery store, restaurants, a number of retail outlets and the constituency office for NDP legislature member Michael Mantha. A hotel is also attached to the centre, which is the largest mall in Elliot Lake.
The city — once an Ontario mining hub — is located about 160 kilometres west of Sudbury.
— By Diana Mehta in Toronto, with files from Paola Loriggio.