No one can ever tell when his moment comes and how he will depart from this life. Very recently, a group of people survived a plane crash and a bus accident in two different countries within the same weekend. Either accident could have seen them all killed, but they survived. As human life is shaped by God, people die at all ages. Children may die when they are yet newborn, in their early years and before they reach adolescence.
Young men die in wars and by accident.
Young women die in childbirth or succumb to killer diseases. Those who live to old age eventually wither away. No one can say whether he will survive the next moment or live for another forty or fifty years. That should be enough motivation for anyone to try to be always ready to meet God, having passed the test of life. While we certainly cannot say when we are going to die, we can influence certain causes of death.