I'm also afraid that my mother will die and no one will notice she's gone for a few weeks and they will find her body all decomposed. I also fear this for myself at times.
This wouldn't happen though as she still works and has friends who would notice she hasn't called or come into work for a while.
When my mother was alive, I had the same fear when I couldn't get a hold of her for awhile. Same when my father in law lived alone in the house next door. I would send my husband over to check on him. Now he lives in an assisted living place where they have to buzz in every day so I feel better.