Gagnon, 99, who hadn't even spent a month in the Residence du Havre in the village of L'Isle-Verte, vanished Thursday as a powerful blaze destroyed part of the building.
She is among the roughly 30 people who were still missing Friday following an overnight blaze that, by the official count, had killed eight residents. Authorities expect that number to rise over the coming days.
As authorities used steam Friday to melt thick sheets of ice off the rubble, friends and relatives of the missing waited to hear if the remains of their loved ones had been recovered.
Gagnon's son, Marc-Henri Saindon, was quickly convinced he would never see his mother again.
"There's no hope," Saindon said Friday as he stood across the street from the ice-covered remains of her home, where firefighters had doused flames in temperatures that hovered around -20 C.
"She only moved in on New Year's Eve. She really liked it there. She was well treated and she had friends there."
Saindon said his family has felt the pain of tragedy before. In 1989, he lost his then-19-year-old son Yves in a fire that followed an explosion at an auto shop.
"Life, eh? We don't get to choose our moments," Saindon said while clutching a framed photo of his smiling mother.
The Saindons weren't alone Friday, as other families in Quebec's Lower St. Lawrence region waited for grim news from authorities.
The deep freeze hampered the work of search crews in L'Isle-Verte, where they sifted through the site of what locals have described as a lively, well-kept seniors' residence.
"The difficulty we have is that we want to be able to find victims but we want to respect the integrity of these potential victims," Quebec provincial police Lt. Guy Lapointe told a news conference.
"So the steam allows us to melt the ice ... without damaging any element that might allow us to go forward in the investigation."
An employee of the residence, who wasn't working the night of the fire, described the home as a warm, welcoming place.
"I lost my friends," said Nicole Belanger, who worked there part-time for the past four years.
"The residents loved us and we loved them."
As she fought back tears, the shaken Belanger said she hadn't left her house since the fire because she couldn't bear to look at the site, even though she can almost see it from her window.
"At a certain point, I will have to go outside," said Belanger, who mostly worked in the laundry department.
"I have no choice but to pass by it."
She said she didn't know which of her colleagues were working the night of the fire.
Most overnight shifts at the residence, Belanger added, were quiet. They involved changing undergarments, handling medication for residents and being available in case someone needed help.
That silence, however, was broken early Thursday morning when the fire alarms went off.
One man who had lived in the 52-unit building for seven years said he awoke to the sirens and immediately understood the gravity of the situation from the haunting shouts.
"I heard screaming outside: 'Save us, there's a fire ... come save us,' " Arnaud Cote, 84, said Friday.
"It was from the people on the second and third floors who were calling for help."
Cote rushed to throw on warm clothing as he prepared to face the cold temperatures outside. But before charging out the doors, he woke up his three neighbours and urged them to get dressed and head for the emergency exit.
Firefighters met them on the security stairs and ushered them from the building to safety, he said.
Police spokesman Lapointe said no causes had been ruled out when asked about a report that a faulty heater may have caused the fire.
On Friday night, however, TVA quoted an employee who was working at the centre Thursday as saying he was "95 per cent sure" the fire was smoking-related and began in a room of one of the residents.
Bruno Belanger told the TV network that, upon hearing the alarm go off, he went to the second floor and saw thick black smoke coming from a room.
Belanger said he went to that particular one because it belonged to a resident he had just dissuaded from going outside to smoke a cigarette.
Lapointe said there was no way of knowing when investigators would be able to retrieve all the bodies.
The search crews announced late Friday they would resume their operations at 7 a.m. on Saturday.
While some 30 people are believed missing, Lapointe said that number could fluctuate.
"People might have been away," he noted. "We want to make sure that everyone who lived there was there or wasn't there. But also the people who might not have lived there who might have come over to spend the night there. We need to check on that too."
Lapointe also called for people who took photos or shot video when the fire broke out to contact authorities to give them a better idea of what exactly might have happened.
Most of the residents probably never had a chance when the blaze erupted — many were over 85, had little or no mobility and were confined to wheelchairs or walkers.
A Quebec Health Department document indicates the residence, which has operated since 1997, had only a partial sprinkler system.
The facility expanded around 2002 and the sprinklers in the new part of the building triggered the alarm.
Fire chief Yvan Charron said his colleagues were able to get to the third of the building that remained standing, while the rest was inaccessible.
The owners of the residence made a public statement Friday for the first time since the fire. They offered their condolences to victims' families.
Roch Bernier and Irene Plante thanked firefighters, volunteers and the residence's employees and said they are co-operating fully with authorities.
The statement made no mention of sprinklers and it said they would be making no further comment for now.
They said it is too early to say whether they will rebuild the residence, mentioning they want to concentrate on relocating survivors.
As the recovery work continued Friday, local grocery-store owner Christian Morin grappled with the possibility he had lost an aunt and uncle, who lived in the seniors' residence.
He also said some of his regular customers were among the missing.
"They'd come by all the time to buy 6-49 tickets, Kleenex, toilet paper, peppermints," he said of his clients.
The visits were more frequent in the summer when it was easier to get around than in the winter. "They were like my big family. I knew them all."
A man he identified as Romeo showed up like clockwork.
"He'd be there at 7:30 and he would check his Lotto Max and we'd talk about hockey and baseball," Morin said. "He's 94 years old."
Nobody had heard from Romeo since the fire and Morin, whose store is a stone's throw from the residence, wasn't optimistic.
Morin's memories are now tinged by the horror of what he saw shortly after he heard the first scream. He first thought he'd left the TV on before going to bed but then he heard more screams and looked out the bedroom window.
"I was witness to something I would never want to see ever again in my lifetime," he said in a trembling voice.
Morin and his wife raced out into the frigid cold to help people flee the homes near the seniors' residence.
"That's when I realized the scope of the tragedy, when I opened my eyes and I saw the residence. I saw desolation, we heard screams, cries for help. It was terrible."
Saindon, meanwhile, struggled Friday to cope with his conviction that he had seen his mother for the last time. She would have turned 100 on April 30, he added.
"She was in perfect condition," said Saindon."Lucid. A memory that was still really good."
_ With files by Sidhartha Banerjee and Nelson Wyatt in Montreal and Alexandre Robillard in L'Isle-Verte