Victims of the Manchester Arena bombing could have survived if the rescue operation had been 'better' and medical help more freely available, a report has found.
"Inadequacies" in the emergency response meant the deaths of two of the 22 victims could have been prevented, although one with only a 'remote possibility'.
But, both were conscious and able to talk with medics as they were placed into ambulances and taken to hospital almost 45 minutes after the blast.
A report into the fatal consequences of the explosion found there was a 'remote possibility' the youngest victim could have been saved if the rescue operation had been conducted differently.
It also found Mr Atkinson "would probably have survived" had there not been "inadequacies" in the emergency response and he had been taken to hospital sooner.
Chairman of the Manchester Arena Inquiry, Sir John Saunders, said his report, looking into the emergency response on the night, also included whether anything "undermined the ability of the response to save life or contributed to the extent of the loss of life".
John, from Radcliffe, was six metres from the bomber and suffered 47 injuries to his legs alone.
He attempted to drag himself across the floor of the City room where a member of the public, Ronald Blake, wrapped a handbag strap around his leg to stem the bleeding.
He was not seen by paramedics for almost an hour, but was conscious and spoke to those helping him.
At 11:47pm - one hour 16 minutes after the blast - and after being moved into the casualty clearing room, he went into cardiac arrest.
He was finally placed into an ambulance at around midnight and arrived at hospital six minutes later, but he could not be saved.
His death was caused by leg injuries sustained in the explosion.
Colonel Clasper, a blast expert, told the inquiry Mr Blake, who applied this makeshift tourniquet, "did brilliantly".
But, despite the "heroic efforts" John Atkinson continued to lose blood, the report said.
Sir John Saunders added that, had more additional steps by qualified first aiders been carried out, it would have stopped or slowed his blood loss - delaying or even preventing his cardiac arrest.
He wrote: "More NWAS paramedics should have been in the City Room before 23:16.
"Responsibility for that failure rests with NWAS. Such treatment would, I am satisfied, have enabled John Atkinson to arrive at hospital prior to having a cardiac arrest and would probably have saved his life."
He added: "John should have been evacuated sooner. If firefighters had been in the City Room shortly after 22:45, and if there has been more ambulances after 23:00 that would have been the case - he would have reached hospital before having a cardiac arrest and is likely to have survived."
Kim Harrison, a solicitor representing 12 families involved in the Manchester arena attack, says John was "left without dignity" to die.
After the findings were published, Mr Atkinson's family said that they hope the North West Ambulance Service will "act rapidly on this report to ensure that no family ever has to go through this horrific experience again."
In a statement, the family said: “It is now clear beyond any doubt that on the night of the bombing John was totally failed at every stage, both by the private medical providers at the Arena, ETUK and the emergency services.
“It is crystal clear that due to those failings, John died from injuries that he could and should have survived.
“As the report says, timely medical treatment to stop or slow John’s catastrophic bleeding and get him to hospital would have saved him.”
Concluding the statement, John Atkinson’s family said: “He was left, dying, without his dignity, on the floor when it should have been obvious to medics that he needed to get straight to hospital.
“As we know from witnesses, John kept asking if he was going to die. John must have known that he was dying and the pain that causes us is too great to put into words.
"This should simply never have been allowed to happen.
“The apology from North West Ambulance Service means nothing unless they act rapidly on this report to ensure that no family ever has to go through this horrific experience again.
“We welcome Sir John’s promise to monitor the implementation of his recommendations. Talk is cheap, and actions speak louder than words.
“We will be watching to see what happens now. We thank the chair for his meticulous and fearless report.
“John will always be in our thoughts and in our hearts. “
Saffie-Rose, from Leyland in Lancashire, suffered 103 injuries, including fractures to her pelvis and legs, and damage to her vascular system and lungs.
She was five metres away from the bomber and suffered massive blood loss.
The eight-year-old was carried out of the Arena on an advertising board before an ambulance was flagged down in the street to take her to hospital.
She died at 11:40pm, more than an hour after the attack.
Experts disagreed over whether the schoolgirl - who was given tickets to see her idol in concert for Christmas - may have survived with better medical intervention.
The Inquiry heard following the blast Saffie-Rose remained in the City Room for 26 minutes, where she drifted in and out of consciousness, at one point giving her name to a member of the public.
She was helped by a number of people including first aiders, police officers and Showsec staff, but no tourniquets or leg splints were applied to her injuries.
Around 20 minutes after the explosion the 'clearly conscious' youngster was put onto an advertising board, and 15 minutes later into an ambulance where she was given "emergency care". At one stage, the report says, Saffie-Rose spoke to ambulance staff.
Father of Saffie-Rose speaks to Elaine Willcox following the release of the inquiry report.
After hearing evidence about treatment which could have been given to Saffie, Sir John Saunders concluded "there was remote possibility of survival" had she been seen by an experienced consultant in pre-hospital emergency medicine immediately, followed by swift evacuation to hospital and expert treatment there.
But, he said, the damage to her lungs was "so severe", and she had sustained extensive blood loss.
He added: "I do not consider that the evidence enables me to say that she had absolutely no chance of survival if the most comprehensive and advanced medical treatment had been initiated immediately after injury."
In response to the criticism of the emergency response, Greater Manchester Fire and Rescue Service said: "Part Two of the Manchester Arena Inquiry Report will look into the response of emergency services the night of the attack and we have done all we can to support this being done in the most open and transparent way possible.
"It is right that we wait for the full report, its findings and recommendations to be published before we comment."
Greater Manchester Police and the North West Ambulance Service say they will comment after the report is published, to allow them to respond to any recommendations made.