Question: According to Buddhism, if one dies in an accident, e.g a car crash, is it due to having done something bad in a past life?
Answer: As accidents are still based on cause and effect at play, and since accidents are unfortunate (if they cause suffering), they are usually the results of negative karma ripening. This needs not be from negative karma of past lives though; it can be from this life too. For example, wilful drink-driving causes loss of mindfulness that can create the ‘instant karma’ of being killed in a crash. If those who perish in accidents do not do so karmically, it would be due to ‘chance’, which does not exist. (If random ‘chance’ exists, there would be records of past Buddhas dying in accidents too!)
Question: Is there an exception, of negative karma not being at play, for those who accidentally die in the course of trying to save others?
Answer: Since the accident of dying in the course of saving others is usually unfortunate, it is still a result of negative karma ripening. What happens is that the person experienced his past negative karma’s ripening while in the midst of creating positive karma. Note that dying in what seems to be an ‘accident’ while saving others might be willing and mindful sacrifice, which is not an accident at all.