I don’t think there is a hierarchy in grief but there are deaths that are more complex than others. Sudden death is devastating. The person you love dying suddenly, coming out of a clear blue sky on an ordinary day is incomprehensible. All the emotions of grief are intensified, grief with the volume turned up is a common phrase.
Often people want to go back and have control, change the story — often caught in endless ruminating and regret so that it is very hard to actively grieve.
People who are bereaved by suicide are a high risk group for alcohol, drug abuse and suicide.
What can help: