This shows that education should start to focus more on building up one's emotional strength and mental well-being. He should have been taught how to deal with bullying. It is tragedic to see how such an apparently happy child is suffering through so much internally.
And even worse, the bullies are also young children who are likely to be suffering from things of their own and in need of help themselves, and Bradley's death, like Shelly-Louise wrote, would likely to haunt them for the rest of their lives. I really don't think it was wise to remind them of their guilt, they are children with emotional weakness too, who might have never imagined things would end up this way.
Tragedy. May his soul rest in peace.