depends on what's gone on around him and how he is discussing it. My 4 and 5 yr. olds have gone through "death obs." times -- actually around 3.5 -- b/c they are exploring the issue.
My great - aunt (89 yrs old) talks to them about the family and show them pictures of her family (our cousins etc. as you can imagine most are -- dead) so they talk about death, and go through these phases about it.
Since I know where they are coming from -- it doesn't bug me out and we talk about it as app. for their age.
Kids do go through "fascination" phases and death is part of life. SO on its own... it could be normal, it depends on how and what he is talking about and why.
at 7:21 PM on Aug. 5, 2009