It is to be expected. You cant be hard on yourself. It was no ones fault, and especially not yours. I know that this is probably one of the hardest things that you will have to deal with/cope with in your life, but you will have to find a way. I have had very close family die right next to me but we expected it. For you this is an unexpected, and i cant imagine the pain, horror, and sorrow that you ar coping with. If you need anything, please dont hesitate to ask myself or for that matter any member of this board. We are all here for the same reason, and that can be expanded to help each other in times of need.
All of my condolences to Marios family friends and acquaintances.