Dream Interpretation? What did my dream mean?

Usually, there is some subconscious reason behind such dreams. May be you're having some worries about members of your family getting hurt( with your sister getting killed and the boy watching his father die). Such thoughts could easily be provoked by something that have happened in your neighborhood/city recently or perhaps something you have seen on the news. Or you might have been watching horror movies before going to bed. So, my point is that it could mean a lot of things, just don't freak out.