That situation happened in two forums I was a member.
On the first one, the dude who died was a programmer, IIRC. Then the emu crew came over the forum and told that he passed away. (or something like that... I remember that I had even posted on that thread).
The second case was easier, cause two friends were using the same account. Then of them died, the other explained the situation (that they had the same account, blah blah) and every gave them condolences, etc.
Torek, if the person has an email, you could send him an email and wait for an answer. XD Ok, if he's dead, you can wait for someone else reply it.