I haven't and don't normally talk about this but, my brother, married and 3 young kids, was found in his room. He was hanging from his belt. We don't know for sure, but think he was doing it for the sexual arousal. His wife was not very helpful or forthcoming with information. At first we thought suicide, but that was ruled out. More information needs to be out there about this kind of stuff.
And it's true, kids just tend to assume they'll live forever. I know we did some things as kids (talking 8-9 years old) that were so stupid I can't even get my head around it. Like lighting stuff on fire in the woods, not thinking about the fact that we were surrounded by hundreds of acres of dry leaves.