I don't think that anything is coincidence. I am so sorry for your loss of loved ones. You are blessed to still have both your parents. Every day should be treated as if it could be their last.
Longevity does not exist in our family. I never knew my grandparents, they died before I was born. I lost my Dad to a heart attack when I was only 7 years old. It shattered my world. I now believe that one event, that changed my life forever made me the strong person I am. Able to handle the many crisis situations my family has faced.
By far the hardest, is the death of a child. My heart goes out to all of you that have suffered that loss. When my daughter died the grief was terrible and I lapsed into post partum depression. If it had not been for my faith in God and the demanding needs of my two year old I don't know if I would have made it.