Domestic abuse survivor Claire Throssell has relived the moment she discovered her estranged husband had murdered their sons in a house fire.
In an ITV News Point of View video, she describes how her 16-year marriage to Darren Sykes began "all roses and romance" but changed when he became "controlling, aggressive", and manipulative.
Claire felt forced to leave the family home in Penistone, and move to her mother's, for the safety of herself and the couple's two young sons. Yet she says her move in fact increased Sykes's harassment.
"He started sending horrible texts to my family," she explains: "He started stalking me. He slashed my tyres. I had to have an app put on my phone so that people knew where I was, in case anything happened to me."
For Claire, an even bigger issue lay in Sykes's permitted contact with the boys.
"It had got to the point where I had to take legal action. I applied to the family courts to make sure the boys had residency with me, and that the boys' wishes and feelings were heard and listened to."
Ultimately, the courts ruled Sykes would be permitted five hours' contact with his sons every week. But, tragically, "in the end, he didn't need five hours to do what he wanted to do. It took just fifteen minutes."
On October 22, 2014, Claire and her mother were just about to have their evening meal when there was a knock at the door. "That'll be the boys coming back early," her mother said, knowing they'd been with their father.
Claire immediately thought otherwise. She explains: "They'd have just opened the door and rushed into my arms, because they were scared to see their dad. They didn't want to see him."
"I opened the door and, as a mum, when you have that instinct, you know. And I knew something had happened and as I opened the door there was a local policeman on the doorstep.
"I saw by his face that something was wrong… and I said: 'What's [Darren] done?"
Claire was told that there had been a fire at the family home and was rushed to Sheffield Children's Hospital. "I don't know if it was the speed of the car, or just the fact I was worried," she recalls: "I was feeling sick the whole way."
She ran in and found medics desperately trying to resuscitate her younger son, nine-year-old Paul. Sadly it was not enough. "As I stood at the side of Paul's bed, the doctor said: 'We're going to let him go now.'"
Claire recalls that moment vividly. "When people say the light goes out of people's eyes, you think it's just a saying but it's true. I held Paul in my arms, and I held him so tightly, and I said: 'Come on Paul, I love you.'
Claire says Paul's hair became "wet with my tears". "He looked at me and smiled and then the light just went out of his beautiful blue eyes. They just turned grey and the nurse just gently closed his eyes, and he fell asleep in my arms."
At this point, still holding Paul, she discovered the truth of her sons' final afternoon together.
On their unsupervised access visit, Sykes had lured the boys up to the attic with the promise of playing with a new train set. He had put out a bowl of sweets and allowed them to play, whilst below them he lit fourteen separate fires using petrol. Sykes even barricaded the property, so as to ensure they could not escape in the ensuing fire, before climbing up into the attic to die with them.
"I found all this out while I was still holding Paul so tightly in my arms. And then they said that I couldn't touch him any more because he was now a crime scene."
Hospital staff then gently laid him in a bed and covered him in blankets. "He looked just like he was sleeping. Just like an angel."
Claire then went over to Jack, whose chest had been cut open by doctors because he couldn't breathe due to the smoke asphyxiation and 56 per cent burns.
"Jack," Claire recalls, "was the little boy with the heart and courage of a lion."
Whilst the brothers were trapped in the attic, the twelve-year-old had tried to save his younger brother by pulling Paul across to the hatch of the attic.
"Unfortunately [Jack] fell backwards and he fell down into the flames. And as he lay on the landing, the fireman cradled him and picked him up. And he found the courage to say to that fireman: 'My dad did this and he did it on purpose.'"
Claire says that Jack repeated this, both to the waiting policeman and the consultant who went on to sedate him to take away his pain in his last moments.
The Children and Family Court Advisory and Support Service (Cafcass) did not interview Jack before he died in hospital five days later. To Claire, it is significant that "that little boy did everything he could to get his voice out there".
Moments after Paul's death, Claire then faced "the worst choice in the world", to leave Paul and go with Jack to Manchester's paediatric burns unit.
"As a mum, you never pick between your children. You just can't. You love both of them and you treat them exactly the same."
"They had to pull me away from Paul and somehow I climbed into the ambulance to Manchester."
Jack "slipped away in my arms" after a fourteen-hour ordeal in the operating theatre.
For Claire, the boys' death sparked her commitment to prevent a future tragedy. "I promised both of them that no other parent would have to hold their children in their arms, as they die, knowing it had been at the hands of the other parent who should love them and cherish them as much as I did."
At their final farewell, the "amazing" local population filled the church to "ensure that Jack and Paul went to their final resting place surrounded by not just my love, but the love of the community that they lived in".
"Everybody was so helpful to me, I was determined that I had to give something back for them."
The Women's Aid charity got in touch six months later, inviting her to be an ambassador for its Child First campaign.
"I knew I had to step up, step forward, and fight for children's voices."
The organisation works to ensure the rights and needs of children are placed foremost in family court decision-making. "When people separate, it becomes a traumatic and tough time. Difficult decisions have to be made and things can turn nasty. And somehow, in that process, the children's voices, wishes, and feelings get lost."
Currently, children aged under 16 are not recognised in their own right by the family courts and are therefore "invisible", says Claire.
Jack and Paul's future was "taken away from them by somebody who simply wanted me to live without them" and live with that pain every day.
"I fight now to make sure that other children have a better future and that anybody suffering from domestic abuse, or violence, or coercive control, can have a place to turn and can escape from it."