That is one of the downfalls of online socializing. When a friend disappears, you often have no way of knowing what happened to them. I've had that happen here on
more than once.
I've also known
friends who have passed away, but their passing was known to another board member and so we all found out and were able to share our grief. In one case we even dedicated an OP on one of the threads to her because she was just such an integral part of the fandom.
Still, when an online friend suddenly disappears and you have no way of knowing if they are alive or dead or what happened to them, it can leave a big question.
I like the idea of an internet service that would notify online friends and group - or help your family or a good friend notify them - in the event of my death. I might have to look into one of those.