As many as 31 elderly Canadians are unaccounted for and five are confirmed dead after a fire destroyed an old people's home in Quebec.
Prime Minister Stephen Harper said there was little doubt the loss of life at Residence du Havre in L'Isle-Verte would be “considerable”.
The blaze was first reported about 00:30 local time (05:30 GMT), 140 miles (225km) east of Quebec City.
Many of the residents used wheelchairs and walking frames, officials said.
Several fire departments from around the region were called to the town of 1,400 to help extinguish the fire. As they battled the blaze, firefighters saw and heard people in the building whom they were unable to save.
Local chief firefighter Yvon Charron told the Canadian Press that it was “a night from hell”.
Emergency crews were able to save about 20 of the home's 50-60 residents, three of whom were injured.
Rescue efforts were slowed by frigid temperatures on Thursday evening, as authorities searching the ruined home were hampered by a layer of ice forming from the fire hoses.
Officials said they hoped at least some of those unaccounted for had been visiting family. “We hope for the best,” Police Sgt Audrey-Annie Bilodeau told reporters.
Most of the residents were over 75 years of age, and 37 were aged over 85. Many were infirm and had Alzheimer's disease, while only five were fully mobile and autonomous, L'Isle-Verte's acting Mayor Ginette Caron told reporters.
“All our thoughts are with the families, the people affected by this ordeal," Ms Caron said.
A recent Quebec health department document suggested the building was only partially fitted with a sprinkler system, but there were smoke detectors in every room and in the building itself.
Quebec Minister of Labour and Social Solidarity Agnès Maltais told reporters on Thursday the government planned to consider incorporating sprinklers into new rules in the future.
“We believe [seniors] are well-protected but we always have to tighten the rules each time we see there's a failure somewhere,” she said. “We're waiting for the result of the inquiry… to understand where the failure is.”