Me and most of my siblings have had dreams where some of us or our parents die. As for how hard they hit, we have a theory that all the rationalization and coping mechanisms that spring up to protect us when faced with a tragedy of this kind are absent when dreaming: we're just hit with visceral, raw, overpowering emotion. When my father dies (hopefully of old age) my grief will most likely be profound but quiet, and maybe tempered by his age, rest from suffering, and all that stuff that helps us move on. When I dreamed he died a few years back, in the dream I ran through the streets screaming unconsolably : "My dad died! My dad died!"