Within 15 minutes, Grenfell Tower in North Kensington, which was built in 1974 and contains 120 flats housing between 400 and 600 people, mostly the poorest from the working classes, was ablaze.
At least 12 people were killed in the blaze that the fire brigade said was unprecedented in its scale and speed. "In my 29 years of being a fire-fighter, I have never, ever seen anything of this scale," said Dany Cotton, commissioner of the London Fire Brigade.
The search was on on Wednesday to identify a miracle baby who was swaddled in a blanket and thrown out by its mother from either the 9th or 10th floor and is said to be safe after somehow being caught by a man who lunged forward to save the child.
The mother disappeared immediately in a fireball, a witness said.
A neighbour, Samira Lamrani, described how she saw the mother trying to save her baby by dropping it from a window "on the ninth or 10th floor" to waiting members of the public below.
Lamrani said she did not see what happened to the baby since her vision was obscured but others confirmed later the baby was safe.
"Around midnight the fire was only around the third floor and then, before you know it, the whole 23 (the right figure is 24) floors of the building were all on fire and there were people screaming for help and throwing kids out," she said. "My family members thankfully made it out. But there are still a lot of people who are unaccounted for."
"I saw a man who flew out of his window, I saw people screaming for help," she said. "We saw a lot of people jumping out that basically didn't make it. It was from the eighth floor and up, and that kind of floor you wouldn't really make it."
Another panicked parent, Joe Walsh, 58, also saw children being thrown out at 2am. "I saw the parent throw two kids out of the window. I don't know where they landed because I was on the other side. I doubt anyone caught them. It wasn't that high up - it would have been the fifth or sixth floor up. There were still people screaming at quarter to four this morning."
A student, Tiago Etienne, 17, confirmed: "I saw children being thrown out of the building from as high as about the 15th floor. They were young - aged probably between four and eight. I saw three thrown out. I think they were being thrown out for the firefighters or police to catch, but I couldn't see from where I was who was at the bottom and what they were catching them in."
Some residents in the burning tower signalled their presence by flashing lights in their flats. George Clarke, an architect, told BBC: "It's so heartbreaking. I've seen someone flashing their torches at the top level, and they obviously can't get out."
Grenfell Tower has been declared structurally safe for the time being, allowing firefighters to enter the building and get up to the 20th floor.
Forty fire engines and around 200 firefighters tackled the blaze. One of them, called Terry, came off duty at midday and described scenes as "something between the (1974 movie) Towering Inferno and the World Trade Center".
An emotional Terry was clear on one point: "It was unbelievable - there was no plan that could have succeeded against this fire."
The cause of the fire has not been formally established. But a caller to LBC, a London radio station, provided vital evidence suggesting the fire began on the 4th floor, when a fridge overheated and exploded because the gas oven next to it had been left on.
Advice to tenants is to stay in their respective apartments in case of a fire because safety measures are in place to retard the flames from spreading internally. Unfortunately, it seems the fire spread externally when the plastic cladding on the outside of the building caught alight. This allowed the flames to work their way into bedrooms whose windows had been left open on a sultry night.
The building was refurbished recently at a cost of £8.6 million. Rydon, the firm that carried it out, said its work "met all required building control, fire regulation, and health and safety standards".
Mahad Egal, who escaped from his flat on the fourth floor with his family, including two small children, just before 1am, said: "The gas pipes that were being installed in the stairwell, that is hazardous and temperamental. This was one of the reasons people were not leaving their flats as they would have assumed it was safer to stay in their flats. The stairwells were full of smoke, dark, scary, and a trip hazard and fall hazard as some lights weren't working. It is incredible we survived."
With a critical shortage of housing in London, local authorities have gone for tower blocks as a way of easing the problem. Grenfell Tower appears to house poor Muslims and whites, blacks and the elderly.
London mayor Sadiq Khan visited Grenfell Tower and said: "There will be a great many questions over the coming days as to the cause of this tragedy and I want to reassure Londoners that we will get all the answers."
-The Telegraph Calcutta
Photos (AP & AFP)