It’s a sad fact but bullying goes on everywhere. It’s in schools, offices and in the community. My sister Lucy was the victim of a long-running campaign which started at school. She has some learning difficulties and she was taunted. She was just 15 when it began and I know she ended up spending a long time hiding in the toilets. That intimidation which went beyond the school ended last week when petrol was poured through the letterbox of our home in Manchester and our house was set alight.

My parents, Alex, 54, and Maureen, 45, died as a result of the fire. As I write this, my sister is lying in intensive care. She is suffering from smoke inhalation and burns to 7% of her body. She has a tube down her throat and she may need a tracheotomy. But she is making progress every day. I don’t know how much she is aware of, but when I told her that when she gets better we are all going to go on holiday, she scrunched up her eyebrows and smiled. Her brain was deprived of oxygen during the fire so we do not know yet what the effects will be. She doesn’t know that our parents have died. It will be my job to tell her.

I don’t think there’s any point in feeling angry. It will just eat me away. But I feel torn in two. I try to meditate when I can and I am getting a lot of support from friends — and complete strangers. A lady came up to me the other day, put her hand on my arm and smiled at me. People have seen me on TV and on the front of the Manchester Evening News. But I do feel frustrated and that is why I gave a press conference last week. I live and work in London, miles away.

My mum hadn’t told anyone about the extent of the intimidation and whom she thought was responsible.

The problem at Lucy’s school started about 18 months ago but I only found out early last year. The school did nothing at first but later expelled two pupils. The bullying, however, was not confined to the school. Even though my sister moved to study elsewhere in Manchester, she remained a target.

My mum had kept the whole problem to herself, taking it all on her shoulders. She seemed to get more nervous as she got older. Dad was always the same — solid. He battened down the hatches.

There is so much I don’t know about what happened. My mum kept diaries of the incidents and log books but they have been destroyed in the fire. I have never even met those who we believe to have caused the trouble. When I heard about them, I wanted to go round and talk to them. But if people don’t have any moral sense, then you can’t present them with a moral argument.

Earlier this month petrol was thrown at the door and my mum called the police. They told her they would install CCTV within a few days and apply for Asbos (anti-social behaviour orders). But nobody came to the house. Now the police ombudsman is launching an inquiry and three people have been charged with murder.

I don’t believe the fire was a drunken prank. I think it was planned. I was in London when I heard the news. It was 4.28am on Thursday, January 12. My uncle rang to tell me that my mum was dead and that my dad and my sister Lucy were in hospital with burns. The first thing I did was to find a picture of my mum — an old Polaroid — and just look at it. My girlfriend had to pick me off the floor.

Another uncle arrived later that morning to drive me up to Manchester. The minutes on the road were just so long. I remember that a song by Glen Campbell, Wichita Lineman, came on the radio and that really cracked me up. My mum loved that song and I do, too.

We went straight to the hospital that afternoon where my grandmother, aunts and uncles were. Suddenly I felt stronger by them being there. It was a terrible thing to be there in the hospital with all of us knowing — or thinking we know — who did this. But we cannot jump to conclusions. The truth must come out.

I went to see my dad. I was expecting to see someone burnt like Ralph Fiennes in The English Patient. But it wasn’t like that at all. He was wrapped up like a mummy but I could see that his eyebrows and eyelashes were burnt. He was heavily sedated. Even though he was unconscious, I talked to him about everything, telling him stories about the past.

The doctors did everything for him but he died three days later, last Sunday. He looked so small when he was laid flat in the bed. He was a substantial man but he was only 5ft 4in and I am 6ft 2in so I could always hug him. I sat with him and it helped me. I told him to go and find my mum and give her a big hug. I also told him that I would do my best for Lucy and with the rest of my life.

He wasn’t my dad, he was my stepfather. My own dad died of cancer when I was three. But he was the only father I knew. He worked as a baggage handler at the airport; before that he was a postroom manager in an insurance company.

My mum was a sales assistant. Neither of them were materialistic. They liked the social side of their work. They were very happily married, blissful I would say. They didn’t have huge expectations of life. We had holidays in Cornwall and they didn’t want flash cars. They weren’t religious, but they had the attitude that if you gave out love it would be returned to you.

The funeral won’t be for at least six weeks or more because of the post mortems and the police inquiry. My mother was so badly burnt that she had to be identified by dental records and jewellery.

I don’t feel vengeful. I have a desire for justice and we have the institutions in place to give us that. For the police to do their job we need to believe in them. I’m not going to spread hate. I do feel hatred and I don’t feel proud of myself. I have to learn to deal with it and not let it destroy my life. I am only 25 and it’s all ahead of me.

I don’t know how or when I am going to tell my sister that our parents are dead. It’s all baby steps for her at the moment and she is under sedation. I will stay strong for her — if I didn’t have her I’d be lost. But what happened will shape all my family’s lives.

David Cochrane was talking to Deirdre Fernand