A fictional drama tells the story of the 7 July bombings in London where four suicide bombers killed 52 people on three tube trains and a bus.
Producer Heather Pescod talks to Newsround about the making of That Summer Day, which will be aired at 4.30pm on 7 July on BBC2 and the CBBC channel.
Why did you decide to make a programme about the London bombings?
The way it started was that after the bombings there were lots and lots of messages on Newsround's website.
Because lots of the messages raised questions about the bombings and how baffling it was that someone could do this to someone else, we felt it was a subject that should be tackled as it was close to kids' hearts.
Why did you decide to do a fictional drama rather than a documentary?
As lots of the questions that children were asking were emotional rather than factual, we thought the best way of handling the information would be through a fictional drama.
How did you set about making the programme?
We went to schools in Hackney and met lots and lots of kids and asked them what was it like for them on the day, what happened to them and how did they feel now about the events - were they worried or concerned about anything?
Lots of the information that's in That Summer Day came directly from kids. There's a bit where pupils thought the bombs were the work of the French because we'd won the Olympics the day before - even though now they feel embarrassed that they thought that at the time.
Similarly, there's a scene in the girls' toilets where they all go to try to call loved ones but they have to hide in the loos as they're not allowed mobiles at school.
There's also an incident with a bus driver at the end which was inspired by one Muslim girl's story.
We took this research and turned it into a piece with six fictional characters at the same London school and what it was like for them during that day.
The school scenes seem really real, how did you do that?
We filmed at the school in the Easter holidays and for a couple of days the pupils came in to be extras.
There's a scene of them queuing up to use the school phone and the big crowd groups, like at the bus stop, all feature the real pupils.
The basketball team is real too and the band is a real school band but from a different school in Hackney and, weirdly, they were meant to be going to a music competition that day, just as what happens in the story.
Was it hard to tackle such a sensitive subject?
As we were making the programme through the eyes of children we didn't need to show graphic images because it's all school-based and not at the bombed tube or bus sites.
It's a scary subject but we didn't want to bury it and pretend it never happened.
We wanted to get it out into the open because we talked to kids' charities like the 7 July Assistance Centre and they said the worst thing to do would be to pretend it didn't happen.
What did you hope to achieve by making a drama about what happened on 7 July?
I think the main thing is to say to children who watch the programme that you're not alone in your fears and concerns that you have had and hopefully they will recognise some of the characters' lives and identify with them.