Jackson tells Maddy what happened on the day of the crash
Five months ago, Arron Peak, 10, and his 8-year-old brother Ben were killed in a motorway crash involving footballer Luke McCormick.
Newsround's Maddy was the first reporter to speak to Ben's best friend Jackson, 8, who was also in the car and survived the accident.
Now, he's campaigning to get drivers to think more about road safety.
"Jackson was sprawled on the sofa giggling when we arrived at his house just outside Manchester.
Maddy couldn't keep up with Jackson on the computer games
He was excited to have the afternoon off school and to be chatting to Newsround.
And he was desperate to show me his skills playing computer games! He was definitely much better than me!
But as soon as he got talking about his best friend Ben and the accident they were both in, his smiles disappeared.
He started fidgeting with his sweatshirt and staring down at the carpet. Sometimes you could see tears welling up in his eyes.
"Me and Ben used to do everything together," he told me. "We'd stay over at each other's houses, listen to cds, do drawing."
Along with their two dads and their brothers they were on their way to a dream day out at the Silverstone race track in June when they were involved in a motorway crash.
Jackson was best friends with Arron and Ben
Their car was hit by 25-year-old footballer Luke McCormick who had been driving drunk, and too fast on his way home from a wedding.
Jackson wasn't hurt. But Ben and his brother Arron were killed, and their dad Phil hurt his back so badly he still has to use a wheelchair.
Jackson said he was devastated when he found out his friends hadn't survived: "There were tears streaming down my face when they told me... I was heartbroken."
He says he still thinks about Ben every single day. They used to be best friends, neighbours and even sat on the same table at school.
Even though he loves driving as fast as he can in computer games, he reckons anyone who speeds on roads in real life is "just an idiot... They shouldn't do it".
Luke McCormick was ordered to spend up to seven years in prison. But Jackson reckons that's not long enough.
We also spoke to Jackson's sister Sophie, who's 11. She was supposed to be having a girly trip out with her mum, sister and Arron and Ben's mum, on the day all the boys left for Silverstone.
Sophie was good friends with Arron
Instead, she woke up to the news they had been in an accident. Later, her mum told her Arron and Ben had died.
"I just screamed and screamed... Now I miss them so much," she said.
Sophie was really good friends with Arron. He'd promised to look after her when they both started high school in September, but Sophie ended up having to go there without him.
I thought it was really brave of Sophie and Jackson to speak to us. It can be difficult or upsetting to talk about people dying.
But they both wanted to explain how sad Ben and Arron's deaths have made them feel, to try to make sure adults drive more safely in future, and something like this never happens again."