Each observer has his own idea about the world, his history, his time. Universal time is a wrapper of the all individual times. Shortly, we conceive the time in its essence like a succession of events and not as a pre-established, existing, and everlasting matrix, in which some events could happen or not. Let us return to our topic. Death is not an action, strictly speaking.
Death is an event only in the sense that it can be recorded in a history.
An analogy for life is a liquid flowing from a reservoir. Death is the moment when the liquid has finished itself and nothing more flows. Whether a person's life ended suddenly, such as by a fatal accident, or slowly at old age, it does not matter. One of our subjective estimation is that the first case is tragic and unfortunate, and the second one is natural. But we actually never knew how much liquid had been in the reservoir.