Grenfell Tower survivors have questioned why it took firefighters 15 minutes from arriving at the building to tackling the initial fire as they said there seemed to be "no urgency".
Witnesses have claimed that initial responders were standing in the lobby on their phones after they arrived to find the that the firefighter's lift was broken.
By the time that they started applying water to the fire in the kitchen of Flat 16 on the fourth floor of the tower it had already spread out of the window and into the cladding, through which the flames spread and claimed the lives of 72 people.
The fire service has already come under criticism from residents for the controversial "stay put" strategy which was not abandoned until 2.47am.
The fire service first arrived at the scene of the fire on June 14 last year at 12.59am, five minutes after the initial 999 call.
They didn't do all the best they can do for us, not at all
The Telegraph can reveal that they borrowed a resident's keys to get into the block. Once inside they discovered that the switch which allows them to override the lift system, was not working and experts say this delayed their entry to the flat.
However, residents have questioned why they could not have gone straight up the stairs.
Farshid Kaficheraghi, 46, believes he was the second person to leave the block after coming out of his 12th floor flat at around 1am when he heard the sirens and has described the 15 minute delay in tackling the fire as "ridiculous".
He said: "The firefighters were not doing anything. They had attached their hose to the emergency water but they were not actually using any hoses. They were just chatting to each other as if they were waiting for some sort of order or command.
"They were inside the building and they had time to do something. There was really no fire at all at this point, just some smoke. There were four engines and about 20 fire fighters.
"They didn't need the lift, they could have just gone up the stairs."
Documents to be examined in detail by the public inquiry on Monday show that they did not enter Flat 16 until 01.08am and did not apply a jet to the fire until 1.14am - 15 minutes after arriving.
By this time the fire had already spread out of the window and into the cladding.
Maryam Adam, who lived next door to Flat 16, said that when she escaped around midnight and saw firefighters "just standing" outside with their phones.
"My husband told them that the fire is in flat 16, the fourth floor, and he replied "we know"," she said, adding: "They didn't do all the best they can do for us, not at all."
A firefighter using a handheld hose first applied a jet to the cladding but below the flames at 1.15am, but was instructed not to direct it at the window as it was unclear who was inside and it was feared it could have pushed steam back into the flat.
Dr Barbara Lane, who will give evidence on Monday, has noted that she can find no evidence of a jet being sprayed at or above Flat 16 in the first 30 minutes of the fire.
The fire engineer said that understanding if external firefighting could have stopped the flames"is of considerable importance" and the reason for the delay "requires further investigation".
However, she stressed that the fire brigade had no idea that the building had been clad in combustible material or that there was a litany of safety failings inside. The regulations only provide for internal firefighting arrangements in high-rise residential buildings.
Mr Kaficheraghi added: "Why did it take them 30 minutes, why didn't they do that from the beginning?"
He is concerned that the the role of the fire brigade in the tragedy is not being examined closely enough as "people love the fire brigade, that is the problem, they don't want to criticise them."
Fatima Alves let the fire brigade into the building after she and her husband Miguel returned home discover smoke and she went wait outside whilst he went to wake their children and neighbours on the 13th floor.
Mr Alves, who ignored the stay put advice, said: "My wife opened the gate at the bottom of the building [for the firefighters] and she opened the inside door also because they needed the fob.
"When I came back down I gave them my fob. It looks like they did not have the key to the building, they should have had a master key.
"Outside they were putting the hose underneath the fire outside the window, not at the flames, and in my opinion if you want to put it out you should put the water on top of the flames not underneath."
Mr Alves said that he had the "utmost respect" for the firefighters who risked their lives on the night to save his friends and neighbours, but the commands that they were following were not fit for for purpose.
"They were just following the rules, but the mistakes were in the rules," he said.
Mr Alves said that the commander should be on the ground to react to events, as the residents of Grenfell were particularly failed by the stay put policy.
Another resident, who escaped early on in the fire from the 12th floor, said that she was concerned that firefighters "did not seem to be in any rush".
The woman, who did not wish to be named, said: "I saw some of the firefighters when I came out of the elevator and they were just standing there watching and taking videos on their phones.
She said that she felt "let down" by the fire service, adding:"If they had evacuated the residents in the early hours everyone might have survived."
Firefighters on the scene have said that the fire was like nothing they have ever seen and they could not have predicted that it would spread so quickly.
A spokesman for the London Fire Brigade said: "The Grenfell Tower Inquiry must be allowed to hear all of the technical advice and expert reports, and all of the evidence about what happened on the night of the fire, without influence.
"London Fire Brigade has and will continue to fully support the Grenfell Tower Inquiry and the ongoing police investigation to ensure everyone understands what happened. Our thoughts, especially from the hundreds of staff who were part of the response to the Grenfell Tower fire, remain with those who died and their families, as well as all those who lost their homes."