LONDON — At least 12 people were killed and 79 others injured – with many others missing – on Wednesday as a fire ripped through a high-rise apartment building in west London where residents had long warned of the potential risk of a catastrophic blaze.

A thick plume of smoke could be seen for miles around, while witnesses reported people jumping from the 24-story building after being trapped by the advancing flames. Children banged on closed windows as they were enveloped by the dark smoke. A woman dropped her baby, desperately hoping someone would catch it in the streets below.

Hundreds of other residents, many who had been asleep when the blaze broke out shortly before 1 a.m., were forced to flee down dark and smoky stairwells. Grefnell Tower, which is located in a poverty-stricken pocket of one of London’s poshest neighborhoods, was engulfed within minutes, said locals.

“It was like a horror movie, smoke was coming from everywhere,” said building resident Adeeb, who hobbled down nine flights of stairs on crutches with his wife and three daughters.

In this photo taken from video, smoke rises from the high-rise apartment building on fire in London on Wednesday. Sky News via AP

Adeeb, who declined to give his last name, said there had been no alarms, and that he only learned of the fire when his daughter woke him.

“She said ‘I can see fire’ and I opened the door and could see smoke,” added Adeeb, who is originally from Syria but has lived in Britain for 16 years. One of his daughters was hospitalized.

The fire raised immediate questions about how a recently renovated high-rise apartment building in the center of one of the world’s wealthiest cities could so quickly become a 24-story inferno, with no alarms or sprinklers to save those trapped within.

London police said 12 people were confirmed dead, while ambulance services said they had taken 79 people to five area hospitals.

At least 40 fire engines responded to the scene, with 200 firefighters involved in a futile effort to contain the blaze. Many rushed into the building wearing breathing tanks, searching floor by floor for survivors even amid concerns that the structure could collapse.

London Fire Commissioner Dany Cotton said a structural engineer was monitoring the stability of the building, but that it was still safe for rescue crews to enter. She said firefighters had climbed as high as the 20th floor to rescue residents and carry them down the building’s stairwell, and that the searches continued.

Smoke billows from a fire that has engulfed the 24-storey Grenfell Tower in west London on Wednesday. Victoria Jones/PA via AP

The fire, which was believed to have begun on one of the lower floors of the 120-unit, public-housing building, was still burning as of 10 a.m. in London, some nine hours after it began.

“This is an unprecedented incident,” Cotton said. “In my 29 years of being a firefighter I have never ever seen anything of this scale.”

Speaking within sight of the burning high-rise – originally white and gray, but most of which had turned a charred black – Cotton said she would not speculate on the exact number of deaths because of the “size and complexity” of the building.

As of early Wednesday morning, people were believed to still be trapped inside a high-rise that is home to about 500 people. Witnesses reported harrowing scenes as residents trapped in top floors leaned out windows, flashing their mobile phone lights and calling frantically for help.

James Wood, a 32-year-old graphic designer who lives in an adjacent building, said he saw a woman at about the 13th floor holding a baby out a window until all hope of a rescue had passed.

“She dropped the baby,” he said. “I’m hoping it was into someone’s arms. But I don’t think the mother made it.”

He said he also saw children, about 5-years-old, banging on a closed window.

“And then it was black smoke. It was all up in flames,” he said. “I know they didn’t make it.”

Wood said he had been part of a campaign to force the borough council to enhance the fire safety in his own public-housing building, but he said the council had not acted.

“Anyone who earns below 10 million pounds a year is not human in this borough,” he said. “They don’t care about fire safety.”

Sajad Jamalvatan, a 22-year-old biomedical engineering student, had been seeing a movie at the nearby Westfield shopping center with his sister when his mom called to say their building was on fire.

Minutes later, he was back in front of the high-rise, and watched a horror scene unfold.

“As soon as I arrived, someone pointed and said ‘someone is jumping, someone is jumping.’ About 16th or 17th floor, we saw a body coming down.”

“Seeing people die in front of you…” he stared at the sidewalk as his voice trailed offf.

He said the blaze had advanced quickly, and that the alarms did not appear to have been triggered. “There are plenty of alarms in the building, but no alarm went off,” he said. “When I arrived, there were 10 flats on fire. After that, the whole building was on fire.”

“It went like that,” he said, snapping his fingers.

Residents said they had heard the faint sound of smoke alarms from individual units, but that it was unclear whether the building had an integrated alarm system. Many said there were only minutes to flee before the building became an inferno.

London Mayor Sadiq Khan said there were “genuine questions that people across the country who live in tower blocks will have. They need to be answered.”

But he said for the time being, the focus is on search-and-rescue – and that it would soon shift to recovery of the dead.

By mid-morning, an acrid smell permeated the area. About 100 people – residents, worried family members and onlookers – stood outside the nearby Rugby Portobello community center. Some were still in their pajamas, having fled in a panic hours earlier.

Neighbors streamed into the center with food. One man pushed a baby stroller teetering with bottles of water, jugs of milk and cans of baked beans.

The building, Grefnell Tower, is located in one of London’s poshest areas, home to celebrities, politicians and wealthy foreigners. It’s just a short walk from Kensington Palace. But the area also includes pockets of poverty, especially in a cluster of high-rise buildings that mark an unofficial western entry point to central London. Authorities said they did not know the cause of the fire, and that it would be investigated.

But residents of the building, which was constructed in 1974 and is used as public housing, had long warned of potential fire hazards even though it was completely renovated just last year.

“It is our conviction that a serious fire in a tower block or similar high density residential property is the most likely reason that those who wield power at the KCTMO will be found out and brought to justice!” a residents organization, the Grenfell Action Group, wrote in a blog post last year.

KCTMO, which stands for Kensington and Chelsea Tenant Management Organization, is the group that runs public housing on behalf of the Royal Borough of Kensington and Chelsea, the west London area where the fire broke out.

On Wednesday morning, the Grenfell Action Group’s web site was updated, with a post on the fire.

“All our warnings fell on deaf ears, and we predicted that a catastrophe like this was inevitable and just a matter of time,” the post read.

Residents said they had been instructed by management before the blaze to stay in their apartments in the event of a fire, and to wait for emergency services to arrive. They said they had been told that their units were fire-proof for at least an hour.

The management company had no immediate comment.

Nick Paget-Brown, who leads the borough council, told Sky News that he had toured the building last May after it was reopened following the renovation. He said hundreds of people were likely in the building at the time of the blaze.

“I’m really not in any position to answer any questions about the structure,” he said. “Clearly there’s a lot more work to do to actually evacuate the building and to establish how safe it is. This is a very, very, very severe fire.”

Neighbors of the London apartment building have sprung into action to help survivors of the fire, donating clothes, food and water and offering shelter.

Churches such as the Roman Catholic St. Francis of Assisi and a nearby mosque are serving as gathering points for donations for those who raced out of the burning building in the middle of the night, fleeing with little else than the clothes in which they slept.

Social media sites have also joined the effort, with some Londoners offering a space on their sofas for those affected by the blaze.

Marco Antoniades, who owns MGA Autos on Latimer Road, says “like in most places in England, people get together and help each other in times like this. That’s what we’re trying to do.”

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