Almost three and a half years after the Manchester Arena bombing, an inquiry is due to start examining whether the atrocity could have been prevented.
Twenty-two people were killed at the Ariana Grande concert in May 2017 after Salman Abedi detonated a homemade bomb as the gig drew to a close. Abedi also died in the blast.
Just three weeks ago, his brother Hashem Abedi was given a minimum jail term of 55-years after a jury decided he had built the bomb with his sibling in Manchester.
The inquiry – which begins on Monday – will analyse what the security services knew about the brothers and whether mistakes were made in the monitoring of their activities.
Figen Murray, who lost her 22-year-old son Martyn Hett in the bombing, told Sky News: “My life feels a bit like a big giant jigsaw at the moment and (the inquiry) gives me the pieces I need to complete the picture.”
Ms Murray added: “Things will never bring closure because with a bereavement of this nature you never get closure.”
Many survivors of the bombing have highlighted the problems they had getting help into the arena in the aftermath of the explosion.
Some emergency responders were initially prevented from entering the area where people lay injured and dying.
Sean Gardner from Cheshire recalls a 25-minute period after the explosion when he was trying to help people with critical injuries.
He said: “The time it took for the emergency services took to enter into the foyer is the big question for me still. It has left some deep scars.
“There was always going to be a five or 10 minute gap but it was 25 minutes before we got any help.
“We were totally helpless. You are trying to deal with a circumstance that’s beyond anyone’s comprehension.
“There’s a lot going on; the noise, the chaos and the screams of pain.”
Mr Gardner was trying to save the life of somebody he didn’t know who was critically injured in front of him.
He added: “As time went on, the more I am losing the person who I was trying to save. That felt like an eternity, I can promise you.
“Would people have been saved 10 minutes earlier if help had arrived? I don’t know.
“Would people have less harmed mentally if people had got in quicker?
“It would be just good to know why the decisions were taken and hopefully accept that they were the right decisions.”
Steve Howe’s wife Alison died in the blast.
He wants the inquiry to establish who took the decisions and why.
“All the police did was stop (the responders) because of information they thought they had,” Mr Howe said.
“Why it took (the police) two hours to realise (Salman Abedi) was on his own. I don’t think it would have helped Alison but there were people they could have helped.”
The independent public inquiry will be led by former High Court judge Sir John Saunders and it is due to finish in spring 2021.