(CNN) -- As search crews worked their way through an ice-coated scene, authorities said Saturday that 10 people had died and 22 were unaccounted for in the blaze that destroyed an elderly community in Quebec.
People grieved deeply in the town of L'Isle-Verten, about 240 kilometers, or 150 miles, northeast of Quebec City. Authorities brought in counselors for the 1,500 residents and a special Mass is planned Sunday for survivors, relatives and residents.
Quebec provincial police Lt. Guy Lapointe said it's unlikely any of the missing escaped the Thursday fire.
"I think we can assume the worst, but you have to understand that we're not going to confirm any deaths until we have actually recovered the remains," he said.
Search teams continued to comb debris for the missing at the Residence du Havre in L'Isle-Verten.
Frigid temperatures have made search efforts difficult, as water used to fight the blaze froze, coating the collapsed three-story building in ice.
"The ice in certain areas is as thick as 60 centimeters. We're talking 2 feet," Lapointe said. "So you can imaging how difficult it is to go through the ice, melt it and again do it in a way that we protect the integrity of the potential victims."
CBC, a CNN network partner, reported that crews are using a machine that produces vapor to melt the ice. The machine normally is used to remove ice from boats.
The cause of the fire that began early Thursday morning at the complex, where at least 52 people were believed to be living, is still under investigation. A lit cigarette is one of many possibilities authorities are looking into, officials said.
At least 37 were older than 85, according to government documents obtained by CBC.
Authorities have brought in more than a dozen psychologists and social workers to counsel the town's 1,500 residents, CBC reported.
"Often, the elderly feel they will bother you if they ask for something, but they don't bother anyone. We have really to repeat the message that we are there for them, to give them all the help necessary," Véronique Hivon, Quebec's junior health and social services minister, said during a news conference.
Father Gilles Frigon, the priest at St-Jean Baptiste de L'Isle-Verte church, plans to lead a special Mass Sunday.
"It's an intimate gathering to help rebuild broken hearts," Frigon told CBC. "It's a first step toward healing, to living our pain and expressing our suffering."
Acting Mayor Ginette Caron told CBC that many of the residents had Alzheimer's disease and used wheelchairs or walkers.
Witnesses said they saw a number of residents calling out to firefighters for help from their windows and balconies.
Pascal Fillion, who lives near the complex, told CTV he heard screams coming from inside, but the fire was so intense there was little firefighters could do.
"There was one person we saw, who they wanted to save, but he was on the top floor, and with the fire and the wind they weren't able to come any closer," he said.
CNN's Anna Claire Stapleton and Elwyn Lopez contributed to this story