My daughter did this and still does to a certain extent. She doesn't seem to want to follow the social "rules" when it comes to death and talks about it inappropriately around others. Around me I try to answer her questions as truthfully as possible and guide her in understanding that others are uncomfortable discussing these things. It was uncomfortable to me at first, the intense way she fixated on trying to understand death, but now I know it is just a natural curiosity for her. I imagine it has to do with the way her mind works, she NEEDS to understand things and well, death, let's face it is something that's very difficult to fathom. My daughter asks people what death feels like, when they will die, and she wants to know how, what, when, where it will occur with her. While she is not as obsessively fixated now, the questions and comments do still occur. She very casually sometimes says very alarming things such as "I will be so sad when you die."