What Really Killed Brittany Murphy

I really dont know..so im asking everythone else. Brittany has always charmed her fans and has always has has critics about her acting. Either with a school girl routine in her movies or a hard-witted tough city chick in some of her films she always managed to give the cameras what they want. Her Career started of slow but hit its pinnacle in the movies Sin City and 8 mile along with co-star’s like Eminem , Clive Owen and Bruce Willis . The question is “what killed this woman”?  Her death is of “Natural Causes” but what in the hell is “natural” death if your only 32? you expect “natural death at 82. despite what it could be there is something going unexplained. Later Brittany has not been in many movies proving that she might of been nursing a imminent illness or ailment? or did this starlet die really because her body couldnt handle her 32 years of life? Maybe drugs or “bad habbits” were involved? Whatever the situation i would like to have everyone opinion on this matter. Tell me what you think caused this young actress to stop breathing.