Manchester first-aider recounts eight-year-old Saffie's tragic last moments.

Dad Paul Reid was leaving the Manchester Arena when he heard a ‘boom’. Instead of running, he ran back inside to help.

It was there he was greeted with a horrific scene: the Arena’s foyer was covered in dust and smoke, and people were “shouting, running and screaming”.

“I will never forget the sounds…[it] was absolute chaos,” the 42-year-old told The Sun.

“There were people lying all over the place.”

Paul - a forklift driver with first-aid training - was one of the first to call emergency services, telling them to "just send everything and anybody to the Manchester Arena, a big thing has happened".

"I was actually looking for a terrorist. I knew it had been a bomb," he said.

After comforting a few injured people, Paul said he saw eight-year-old Saffie Rose Roussos, lying near the exit door.

"I saw the little girl was conscious and I said, 'What’s your name?'" Paul said.

"When I asked her how old she was she said she was eight. I wanted to keep her talking and asked her if she had enjoyed the concert but then I realised she was having difficulty breathing.

"She said, 'Where's my mum?' I said to her, 'I don’t know but we are going to find her in a minute. Don't worry. We are going to sort it out. You are going to be all right'."

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He said the little girl asked him what had happened, but Paul didn't know what to say.

"I just tried to reassure her, then one of the paramedics came," he said.

"The girl kept trying to fall asleep but I knew I had to keep her awake and conscious. I was stroking her face and saying, 'Come on [Safie] stay awake. You're going to be all right. They are coming to take you away in a minute.'

"But she kept drifting into unconsciousness. I cannot bear to think about it. Then she started shivering and told me she felt cold. I took my coat off and put it over her but she was still shaking a bit."

Saffie was taken outside on a makeshift stretcher and loaded into an ambulance.

"She is still alive with her eyes open. That's the last time I saw her," Paul said.

It wasn't until the next day, when Paul saw the news, that he learned the eight-year-old had died from her injuries.

"I saw the pictures and knew it was the child...We did our best to save her but in the end no one could.

"I only knew her for a few minutes but I will never forget her," he said.

Saffie is the youngest known victim of the attack, which killed 22 people and left 119 others injured.

15 people, including Saffie, have been formally identified as having passed away in the attack.

It's been reported that Saffie's mother, who was with her at the Ariana Grande concert, is still in a coma in hospital and is unaware of her daughter's death.

If you'd like to support the victims of the attack and their families, you can donate to the Manchester attack victims fund here.