Suppose a person X had a severe accident, body almost completely destroyed. If we think of X only as a body, then he will surely die as the body cannot support further life. But we define death as soul leaving the body. Therefore it is soul that should initiate the process of death. Yet we see that deaths take place when the body cannot support further life. That is why, we have medical reasons like Heart Attack, Cancer, Accident, Old age etc. for almost every death on the planet. How is this fact (of soul leaving the body only in poor condition) explained in light of our well-established knowledge that it is departure of soul that causes death?
In other words; if a person is destined to die at a certain time, why there has to be a bodily cause (disease, accident, fall etc.) before to produce death as effect ?
Do we have something in any scripture related to this?
[EDIT: Removed the controversial part: "Soul not attached to body"]