According to Mexico's navy, there are no missing children from Enrique Rebsamen school in Mexico City. Assistant Navy Secretary Angel Enrique Sarmiento said Thursday afternoon that the navy "never had any knowledge" of a schoolgirl trapped in the rubble. Sarmiento said there there is evidence a person may still be alive, probably a school worker. (Sept. 21, 5:57 p.m. ET)


See CBC News's later story on the rescue efforts.
 

A delicate effort to reach a young girl buried in the rubble of her school following Tuesday's earthquake stretched into a daylong vigil for Mexico, much of it broadcast across the nation as rescue workers still struggled in rain and darkness early Thursday trying to pick away unstable debris and reach her.

The sight of her wiggling fingers early Wednesday became a symbol for the hope that drove thousands of professionals and volunteers to work frantically at dozens of wrecked buildings across the capital and nearby states looking for survivors of the magnitude 7.1 quake that killed at least 245 people in central Mexico and injured over 2,000.

Rescuers said the girl told them her name was Frida Sofia.

Vladimir Navarro spent the night working at the site of a collapsed school. The university worker said rescuers are "just metres away from getting to the children," but the rubble is unstable and they can't access it until it is shored up.

"Taking any decision is dangerous," Navarro said, adding they need a large crane to come in and help. 

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Rescuers from Israel help in the search for survivors in a flattened building in Mexico City on Thursday. (Yuri Cortez/AFP/Getty Images)

Late Thursday morning, rescuers were trying to reinforce what's left of the school as part of the efforts to free Frida Sofia. 

The remains of the building had shifted dangerously earlier Thursday morning, prompting some rescuers to evacuate the top of the rubble pile. 

Workers are using iron beams to prop up the structure. It took a dozen or more men to carry each one. 

Stretchers have also been brought to the edge of the building. A large crane is also on site. 

The death toll rose after Mexico City Mayor Miguel Angel Mancera said the number confirmed to have died had risen from 100 to 115. An earlier federal government statement had put the overall toll at 230, including 100 deaths in Mexico City.

Mancera also said two women and a man had been pulled alive from a collapsed office building in the city's centre Wednesday night, almost 36 hours after the quake.

'You still hear people in there'

Even as President Enrique Pena Nieto declared three days of mourning, soldiers, police, firefighters and everyday citizens kept digging through rubble, at times with their hands gaining centimetres at a time, at times with cranes and backhoes to lift heavy slabs of concrete.

"There are still people groaning. There are three more floors to remove rubble from. And you still hear people in there," said Evodio Dario Marcelino, a volunteer working with dozens of others at a collapsed apartment building.

A man was pulled alive from a partly collapsed apartment building in northern Mexico City more than 24 hours after the quake and was taken away in a stretcher, apparently conscious.

In all, 52 people had been rescued alive, the city's Social Development Department said, adding in a tweet: "We won't stop." It was a race against time, Pena Nieto warned in a tweet of his own saying that "every minute counts to save lives."

Focus on collapsed school

But the country's attention focused on the collapsed Enrique Rebsamen school on the city's south side, where 21 children and four adults had been confirmed dead.

Hopes rose Wednesday when workers told local media they had detected signs that one girl was alive and she speaking to them through a hole dug in the rubble. Thermal imaging suggested several more people might be in the airspace around her.

A volunteer rescue worker, Hector Mendez, said cameras lowered into the rubble suggested there might be four people still inside, but he added that it wasn't clear if anyone beside the girl was alive.

'She is alive'

Dr. Alfredo Vega, who was working with the rescue team, said Frida Sofia had been located alive under the pancaked floor slabs.

Vega said "she is alive, and she is telling us that there are five more children alive" in the same space.

Education Secretary Aurelio Nuno confirmed that the girl was alive, but said it was still not confirmed if other children were also alive under the rubble. Strangely, Nuno said, no relatives of a girl named Frida could be found.

While optimism ran strong for the girl's rescue effort, only four corpses had been found in the wreckage during the day, Mendez said, and workers were still trying to get to the girl as the operation crossed into a new day.

Rescuers carried in lengths of wide steel pipe big enough for someone to crawl through, apparently trying to create a tunnel into the collapsed slabs of the three-storey school building. But a heavy rain fell during the night, and the tottering pile of rubble had to be shored up with hundreds of wooden beams.

Neighbourhoods unite

People have rallied to help their neighbours in a huge volunteer effort that includes people from all walks of life in Mexico City, where social classes seldom mix. Doctors, dentists and lawyers stood alongside construction workers and street sweepers, handing buckets of debris or chunks of concrete hand to hand down the line.

At a collapsed factory building closer to the city's centre, giant cranes lifted huge slabs of concrete from the towering pile of rubble, like peeling layers from an onion. Workers with hand tools would quickly move in to look for signs of survivors and begin attacking the next layer.

Government rescue worker Alejandro Herrera said three bodies had been found Wednesday afternoon at the factory.

"There are sounds [beneath the rubble], but we don't know if they are coming from inside or if it is the sound of the rubble," Herrera said.

In addition to those killed in Mexico City, the federal civil defence agency said 69 died in Morelos state just south of the capital and 43 in Puebla state to the southeast, where the quake was centred. The rest of the deaths were in Mexico state, which borders Mexico City on three sides, Guerrero and Oaxaca states.

In Atzala in Puebla state, villagers mourned 11 family members who died inside a church when it crumbled during a baptism for a two-month-old girl. People at the wake said the only ones to survive were the baby's father, the priest and the priest's assistant.

Power was being restored in some Mexico City neighbourhoods that already spent a day without power. The mayor said there were 38 collapsed buildings in the capital, down from the 44 he had announced previously.

Canadians in Mexico

There are currently 3,320 Canadians known to be in Mexico. Registration with the federal government is voluntary, however, and that figure "may not reflect the actual number," said Philip Hannan, spokesperson for Global Affairs Canada. 

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A rescuer and a firefighter search for survivors in a flattened building in Mexico City on Thursdaytwo days after a strong quake hit central Mexico. (Yuri Cortez/AFP/Getty Images)

"As of Wednesday morning, there have been no reports of Canadian casualties," he said. 

In a statement issued Tuesday night, Foreign Affairs Minister Chrystia Freeland said, "The government of Canada is ready to assist Mexico as needed and appropriate."

She stressed that Canadians requiring consular assistance should contact Global Affairs toll-free at 1-613-996-8885 or by email at sos@international.gc.ca.

Terrifying moments during Mexico quake2:14

With files from CBC News