London highrise death toll at 12 but 'will sadly increase,' say police

London fire crews are still on the scene of a massive apartment tower fire that killed at least 12 people and left dozens injured some of them critically.

When the fire started in the early morning hours, flames could be seen shooting from windows in the24-storeyGrenfellTower in NorthKensingtonandplumes of smoke stretched for kilometresover the British capital as more than 200 firefighters battled the blaze.

Between 400 and 600 people were said to live in the building, which housed120 apartments. It is unclear how many people were inside the building at the time and how many were able to escape.

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"This evening crews werecontinuing todampdown pockets of fire and will remain at the scene throughout the night and into tomorrow," a statement from fire officials said.

Residents who made it out of the building reported thick, choking smoke and absolute panic as people tried to figure out what was happening.

Nassima Boutrig, who lives across from the building, said she was awakened by sirens and smoke so thick that it filled her home as well.

"We saw the people screaming," she said. "A lot of people said, 'Help! Help! Help!' The fire brigade could only help downstairs. They couldn't stop the fire."

One man who lived near the tower toldCBC'sAs It Happensthat he saw a "wall of fire."

"I'm mean, we're talking about24storeysof fire, right at the end of your road," Tim Downie said.

Earlier in the day, authorities had asked residents who had escaped to contact a help line so they could be accounted for.

"It is very important we identify and account for everybody. Our priority is clearly those that would have been residents of [Grenfell Tower]," Metropolitan Police Cmdr. Stuart Cundy said in a statement.

Cundy also said 65 people had been rescued from the building, not including those who escaped on their own, but he didn't expect any other survivors to be found inside.

By evening, it remained unclear how many people were missing.

In a statement released Wednesday night, fire officials said a structural engineer and specialized urban search and rescue teams had checked out the tower and determined that "it is not in danger of collapsing and that it is safe for our crews to be in there."

In a video statement posted to Twitter, the director of operations of London Ambulance Service provided updated figures.PaulWoodrow said 68 people had been transported to six different hospitals for treatment.

"Eighteen of those patients currently require critical care," he said.

'Unprecedented incident'

Earlier in the day, Dany Cotton, commissioner of the London fire department, told reporters the fire"is an unprecedented incident."

"In my 29 years of being a firefighter, I have never, ever seen anything of this scale."

Cotton told a news conference that some firefighters sustained minor injuries and the fire brigade will likely be on the scene for 24 hours.

She would notspeculate about the cause of the fire or how it spread so rapidly over the whole tower block.

Ambulances and fire trucks filled the streets around the building located in a diverse, working-class area of London. Nearby residents, some carrying pets,were also forced out of their homes. Volunteers were handing out bottled water.

Others searched for information at makeshift evacuation centresset up at churches and recreation centres.

'Our warnings fell on deaf ears'

Grenfell Tower was built in 1974, according to the Royal Borough of Kensington and Chelsea.In May 2016, a $14.5-million renovation was carried out on the tower, including adding new cladding and windows.

The construction firm that did the work said it "met all required building control, fire regulation, and health and safety standards."

Massive apartment building fire in London

7 years ago

Duration 1:43

Dozens of people injured, several dead as structure engulfed in flames

The renovation project included installation of insulated exterior cladding, double-glazed windows and a communal heating system.

Investigators need to look at what materials were used in the project and who approved their use, said Joe Ruane, the former deputy chief fire officer for U.S. air force bases in Britain. But he said the speed with which the fire spread suggests that more than one fire protection safeguard failed.

"It's not just one thing," Ruane said. "It's multiple issues."

The Grenfell Action Group, a community organization formed to oppose a nearby redevelopment project, has been warning about the risk of fire at Grenfell Tower since 2013. The group has raised concerns about testing and maintenance of firefighting equipment, and blocked emergency access to the site.

A building plan of GrenfellTower released by the British Press Association shows a single staircase in the middle of the tower.

"All our warnings fell on deaf ears and we predicted that a catastrophe like this was inevitable and just a matter of time," the group said in a blog post written after the fire broke out.

The manager of the GrenfellTowersaid it is too early to speculate what caused the inferno and what contributed to its spread.

TheKensingtonand Chelsea Tenant Management Organization said it will co-operate fully "with all the relevant authorities in order to ascertain the cause of this tragedy."

"We are aware that concerns have been raised historically by residents. We always take all concerns seriously and these will form part of our forthcoming investigations. While these investigations continue with our co-operation, our core priority at the moment is our residents."

Mayor wants answers

London Mayor Sadiq Khan saidquestions need to be answered about the safety of towerblocks.

"Across London we have many, many tower blocks, and what wecan't have is a situation where people's safety is put at riskbecause of bad advice being given or if it is the case, as hasbeen alleged, of tower blocks not being properly serviced ormaintained."

Prime Minister Theresa May's Downing Street office said she was "deeply saddened by the tragic loss of life in the Grenfell Tower and is being kept constantly updated on the situation."