One cannot generalise on bereavements because they take different forms. When an elderly person comes to a peaceful end after a long and satisfying life, that can be accepted without trauma, knowing it is in the nature of things, and of course is expected.
It is when death happens unexpectedly that the trauma is experienced. I was asked to visit a mother who had just lost her little daughter with cancer. She was two years of age. Sometimes a husband or wife is taken in the prime of life when the family sorely needs them. A strong and healthy sportsman is stricken with a fatal disease.