"All our warnings fell on deaf ears and we predicted that a catastrophe like this was inevitable and just a matter of time", they said.
Local residents said they had warned local authorities about fire issues in the building, a public housing block built in 1974 and containing 120 homes, according to the Royal Borough of Kensington and Chelsea.
Samira Lamrani said: "The windows were slightly ajar, a woman was gesturing that she was about to throw her baby and if somebody could catch her baby". Some said no fire alarm sounded.
"Somebody did, a gentleman ran forward and managed to grab the baby".
Thirty people have been taken to five hospitals, LAS said. "In my 29 years of being a firefighter, I have never ever seen anything of this scale".
"As I was going down the stairs, there were firefighters, truly fantastic firefighters that were actually going upstairs, to the fire, trying to get as many people out the building as possible", said a witness.
Other witnesses said they saw residents holding their children out of windows.
Khan says in a statement "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". "I just hope they have got everyone out", he said.
Witnesses described people leaping from the building and of trapped children banging on windows as the fire broke out at around 1 a.m. local time as people slept. I saw it engulfed in flames.
Construction firm Rydon, which completed a refurbishment of Grenfell Tower in 2016, said it is "shocked to hear of the devastating fire" adding that the work "met all required building control, fire regulation and health and safety standards". High-rise buildings are typically created to contain fire outbreaks within floors, so it is often safer to stay in an apartment unaffected by a blaze.
The service says a major incident has been declared in the west London after a fire broke out in the early hours of the morning.
He said he heard sirens, helicopters and shouting and then saw the building engulfed in flames.
Firefighters were on the scene within six minutes.
More than 200 firefighters were sent to tackle the blaze which was reported just before 1am on Wednesday.
But this fire seemed to tear up the building from the outside, gutting the outer apartments and blackening most of the facade.
More than 20 ambulance crews were at the scene.
"It was clear that the fire service could not cope with the fire".
In a statement posted to Twitter early Wednesday, London police say two people are now being treated for smoke inhalation and they're waiting updates on further injuries.
Earlier, George Clarke, a television presenter living close to scene, told BBC Radio that he saw people on the top floor of the block flashing their torches.
A cross section of the Grenfell Tower, used in the 2012 regeneration plans.