To dream about the death of a loved one suggests that you are lacking a certain aspect or quality that the loved one embodies. Ask yourself what makes this person special or what you like about them. It is that very quality that you are lacking in your own relationship or circumstances. Alternatively, the dream indicates that whatever that person represents has no part in your own life anymore. In particular, to dream about the death of your parents indicates that you are undergoing a significant change in your waking life. Your relationship with them has evolved into a new realm.
To see someone dying in your dream signifies that your feelings for that person are dead or that a significant change/loss is occurring in your relationship with that person. Alternatively, you may want to repress that aspect of yourself that is represented by the dying person.