My son is the same way to the tee! He was hit by a car, his father was in a 3-car head-on collision, and he (son) burned our house down! I thought he was going through some after-shock stuff, but I found out he is Bipolar and learned new ways to deal with his outbursts. I'm not saying your son is, but I would definitely have a doctor check him out. Our outbursts are much less and now that I know what and when it is occurring, I hold him and love him instead of disciplining him(or both). Good luck!
Do you manage to do "fun" things together often enough? It sounds like (unless there is an organic cause for his behavior) there may be something missing in your relationship. Take him for a walk, play a game, ride a bike together.
If your son is successful in school, among friends and in out-of-home situations, it is likely that a systematic program of behavior management will make a difference. It's going to be important for you to take the bull by the horns and be very consistent and persistent. Relative to an effective approach, read Lynn Clark's book SOS: Help for Parents (Parents Press, Bowling Green, Kenticky). The approach is ideal for children like your son. Also, seek out an appointment with a child menatl health clinician. Such professionals can help you figure out what is going on, rule out any other emotional problems, and design an approach to manage the behavior.