Bradley is one of the children taking part in Newsround's special programme about death, called Gone. His Dad died in May 2006.
Katie's brother was killed in a road accident in December 2008. She found it important to think of the happy times they shared when he was alive.
Sarika's mum died in November 2005. She found it difficult to deal with her own emotions, and those of her Dad but counselling helped.
Joe's Granddad died in March 2007. He gave Joe a watch that helps him remember the time spent together. He says it's important to talk to people when someone dies.
Barney is the presenter of Gone. The prgramme is on the CBBC Channel on Monday 30 March at 6.30pm and is on BBC1 on Tuesday 31 March at 4.55pm.