For whatever it may be worth, while I have real doubts about it being as CS Lewis seemed to suppose, it seems to me reasonable that there was innocent death, by apparent mishap or other things, unrelated to sin. If the 'natural' order of things is the same now as it was then, leaves became dirt because of earthworms, who got squished sometimes. Death occurred. I have no problem with microbes which seem to die at pretty much the same rate as they multiply, depending on available sustenance and protection from UV rays, and so on.
CS Lewis' space trilogy suggests intelligent life on other planets, (allegorically, but with humor and depth), one race of which goes on hunts for a shark-like being, in which hunts sometimes a hunter is killed. Also, there are those who by mishap get bashed in the head or otherwise lose their mind and need to be 'un-made' by the Ruler of the planet (the Angel assigned to that planet, as Lucifer was assigned to this one). Fun books, btw.
As is seen, particularly in the last two books, the way of sin and the way of this present age stands in STARK contrast with the simple principle of life and death. I think that living and dying physically has little to do with the perversion, presumptuousness and self-promotion/self-importance that is sin.
To me, the view that a lot of believers seem to espouse, that physical death and suffering is only a result of Adam's sin (and any subsequent sin) is almost superstitious. It also doesn't put sin into the category of abominable evil in which it belongs—the feel of incongruity against reality, that the creation can REBEL against the Creator.
I have no problem with the idea that the Creator would snuff out a life for whatever reason he has to do so. But that's rarely what is argued against, (as though some would think that God would have no right to do that). But what is argued as basic in most any FreeWill debate is that sin implies an awful thing for which we lack proper adjectives. Not mere physical death.
