A firefighter has recalled the moment he tried to text his mother after collapsing, low on oxygen, in the smoke-logged stairwell of Grenfell Tower.
Chris Secrett, a crew manager from North Kensington, knew he was in "big trouble" after his breathing apparatus oxygen supplies began running out on the 20th floor.
He had been part of a three-man team searching in vain for stranded 12-year-old Jessica Urbano Ramirez, who died after fleeing to the 23rd floor.
In a written statement published by the Grenfell Tower inquiry, he recalled how the temperature had "just soared" at the point the warning whistle sounded on his kit.
Breathing tanks offer around 35 minutes of air without intense exercise, but the team had been forced to leave the lift at a lower floor and walk up.
The firefighter collapsed to the ground and crawled to the stairwell through the "unbearable" heat, with colleagues David Badillo and Chris Dorgu.
"I knew we were in trouble; it was just too hot and I was running out of air. We were also really high up in the building and no one was coming to get us. We just had to get out," he wrote.
Mr Secrett passed through "thick" smoke on the stairs in a "a mixture of stumbling, falling and crawling", before realising Mr Dorgu had vanished.
"I looked at my gauge and saw I only had 15 bar left; I was in big trouble", the statement continued.
"I put myself in a corner of the stairwell because I did not want to be in anyone else's way if I didn't make it out.
"I tried to get my phone out of my pocket to text my mum but I couldn't get the phone out."
Mr Dorgu suddenly appeared and dragged them both down the stairs.
Mr Secrett rested outside for around 20 to 30 minutes before springing back into action, helping paramedics move a man who appeared dead.
The victim was "unconscious and had black soot round his face" and his head was banging on the floor as he was being carried, prompting the firefighter to intervene.
He then began ferrying casualties from the tower, most of whom "did not appear to be alive", his statement said.
Like his colleagues before him, Mr Secrett's account painted a disturbing picture of the inferno's ruinous impact.
"It was raining debris everywhere. Clumps of metal and insulation were falling off the tower, most of which was on fire," it said.
He was forced to start extinguishing debris after spotting "taxis and mopeds nearby catching fire", along with a turntable cage belonging to a crew from Paddington.
A sheet of glass shattered over his face, while he also witnessed a firefighter being hit by a body falling from the tower.
When Mr Secrett first arrived, he acted as a liaison between the incident commander Michael Dowden on the ground and the team extinguishing the fourth-floor kitchen fire.
Mr Dowden became "a bit flustered" and ordered more fire engines despite crew manager Charles Batterbee assuring him the internal blaze was out.
He wrote: "I told him to slow down because the fire was out. I realised something was amiss... by now there was lots of radio traffic.
"It transpired although the fire had been extinguished inside the flat, the fire was travelling on the outside of the building. This is something that can happen and I have seen before. Fire can spread to the flat above via the window."
Describing what he eventually saw, Mr Secrett said: "The whole side of the building was on fire and there was no way we are going to put that out quickly.
"It was now a significant fire which I would describe as raging and very fierce.
"The heat radiating was really intense. I could see a lot of sparking and fizzing of fires spreading everywhere. It was a big wall of fire and so intense.
"Whatever was fuelling it was doing a good job."