sylvania - I am so sorry to hear about your loss.
It is part of the human condition, and the grieving process, that we try and find rational reasons why a sudden death has occured.
A vital part of grieving and moving on with life, is trying to set things in order - with reasons for circumstances, and at the moment, you are denied this, hence your distress.
I hope that some of the qualified answers you have recveived have helped, and that ultimately, you will receive a definitive answer which will help you to deal with your loss.