Delays getting paramedics and emergency responders to the aftermath of the Manchester Arena bombing may have cost lives, an inquiry has heard.
It was 19 minutes after the explosion before the first paramedic got into the foyer of the arena where people were dying and critically injured.
The public inquiry into the atrocity heard that a "significant issue" is whether some people who died could have survived had they received better and faster medical help.
Ronald Blake, who was picking up his daughter from the arena with his wife, rang police seconds after the explosion.
His dramatic 999 call, in which he could be heard trying to help John Atkinson, 28, as he lay suffering from serious leg wounds, was played to the inquiry.
When the operator asked if anyone was injured, Mr Blake replied: "Yes, loads. It's absolutely manic."
He added: "There's about 30 or 40 injured. I'm with a man that's really injured."
When Mr Blake told the operator "you've got my number" he was asked to stay on the line and tie a belt around the top of Mr Atkinson's leg.
Mr Atkinson, a support worker for people with autism from Manchester, was eventually evacuated from the scene at 11.17pm, 46 minutes after the explosion.
The injured were being carried out on makeshift stretchers made from cardboard and crowd control barriers.
At 11.47pm, an hour-and-a-quarter after the explosion, chest compressions were started on Mr Atkinson by a paramedic after he went into cardiac arrest.
Mr Atkinson did not survive.
Paul Greaney QC, counsel to the inquest, said: "The issue of John Atkinson's survivability is a significant issue for the inquiry to consider."
Mr Greaney added that Mr Blake had "comforted John Atkinson, a stranger to him, for just over an hour".
He added: "Mr Blake's conduct showed, in our view, the best of our community."
Minute-by-minute images from the CCTV showed emergency responders arriving at the arena.
The suicide bomber, Salman Abedi, detonated the bomb in his backpack at 10:31pm in the City Room, a public thoroughfare where people accessed the arena. At the time the Ariana Grande concert was coming to an end.
British Transport Police officer PC Jessica Bullough said in a statement: "I ran into the City Room and I can only describe it as a war zone there.
"There were a number of casualties on the floor, blood everywhere and the whole place was smoky and, in my words, was carnage...there were nuts and bolts scattered everywhere."
The bomb had killed 22 people and injured many others - many more suffered deep psychological injuries from what they saw.
Survivors have long questioned why it took so long to get emergency responders in to help people.
Of the teams of paramedics that eventually arrived, only three actually made it to the City Room where the explosion happened.
The crews of firefighters were also not allowed in to help - it was two hours and six minutes after the explosion before they were given access.
During that time the police were also receiving multiple reports of other potentially linked incidents around Greater Manchester, including a suspicious package at a hospital and a potential second terrorist.
Mr Greaney said: "It is important we acknowledge the pressure that those who responded to the attack at the Manchester Arena came under.
"It must, we acknowledge, have been enormous.
"Which of us who were not there and not required to make critical decisions in the agony of the moment can understand what that felt like?"
The inquiry will examine whether Greater Manchester Police learnt enough lessons from a training exercise 10 months earlier which anticipated a marauding firearms terrorist attack in the area around the Arena.
Experts for the inquiry believe the force needs to explain "significant flaws" in their response on the night of the bomb.
Mr Greaney said that the inquiry, which will run into spring 2021, would "probe deeply, but fairly, into what happened".
The suicide bomber's brother, Hashem Abedi, was jailed last month for a minimum of 55 years for his role in building the bomb.