No central fire alarm rang inside the 27-storey tower block as the blaze took hold and sprinklers failed, said furious residents who escaped London's towering inferno today.
At least 30 people had been taken to five hospitals after the fire at Grenfell Tower in north Kensington - but dozens are feared missing and the fire service said there "have been a number of fatalities". It is not yet known how many people perished.
More than one resident has claimed there was no central fire alarm system for the tower block - or it had failed - and only smoke alarms in individual flats were working, according to the Daily Mail.
There are also claims that there that there was no central sprinkler system - or it was also not working properly during the fire.
Others have claimed that the new cladding added during last year's £10 million ($17.5million) refurbishment caught alight "like a matchstick".
Paul Munakr lives on the 7th floor and told BBC News: "I managed to get out the building, not by a fire alarm, or something like that, it was by people down below screaming to people, don't jump, don't jump off the building.
"Now, honestly I don't know for certain if people jumped off the building to get away from the fire, but the main thing for me is the fact that the fire alarms didn't go off in the building."
Many residents have said they were only alerted to the fire by neighbours banging on doors or phone calls from people living in the area.
Former chief fire officer for the Midlands, Jon Hall, who advised David Cameron's government said today: "This is a Third-World type accident that represents a failure of every component of fire safety and building management.
"How can this possibly happen in 2017? Sadness and so many professional questions."
Residents have claimed they had been told to stay in their flats if there was a fire and wait to be rescued.
One man, who fled from the seventh floor with his family, said: "We were told very clearly that if there was a fire we should stay there because it is fire proof for an hour and by that time we would have been rescued.
"If I had listened to that I wouldn't be here now - I knew I had to get us out of there."
One man who escaped from the 17th floor with his aunt, 68, told Channel 4 News: "We saw the fire engines, so we were looking outside at what's going on.
"There was no fire alarms anywhere, because we don't have a kind of integrated fire system - it's just everyone's house for itself.
"I walked out into the common area to see if the lifts are moving, to see if people are in a hassle - nothing. But I could smell the smoke.
"I went back inside the house, looked out the window. I started looking down the window - I had to really pull myself out to look down the window, from the 17th floor, and I see the fire blazing, and coming up really fast, because of the cladding - the cladding was really flammable, and it just caught up like a matchstick."
Another said he lived in one of the top floors and said he heard no alarms when the blaze started.
He said: "I heard my neighbour's smoke alarm go off, and thought nothing of it. Then I heard a neighbour shouting. I'm lucky to be alive - and lots of people have not got out of the building."
Zeinab Jafari said: "There wasn't any other fire exit, except the staircase where the fire was coming.
"My youngest sister-in-law and my father-in-law were stuck. I was taken out but then lost contact with my father.
"The building has been redone on the outside, a cover - some kind of plastic has been put on it and the windows done.
"The fire went under a new cover, which had been put on with wooden slats. Most of the residents were worried about this.
"We had meetings about the works and were worried it would happen."
An action group at the tower block have said their warnings fell on "deaf ears" after highlighting safety concerns about the block.
The cause of the blaze is not known, but a November 2016 blog post from the Grenfell Action Group said "only a catastrophic event" would expose issues residents had.
Several hundred people would have been in the block when the fire was reported at 1.15am on Wednesday. Thirty have been taken to hospital.
The group said there was one entry and exit to Grenfell Tower during improvement works at the block in Latimer Rd and it had issues with evacuation procedures at the building.
After the fire, the group posted: "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 claimed access to the building was "severely restricted" for emergency services and other vehicles and that residents were advised to stay in their flats if there was a fire.