I'm wondering why all connected comments and answers(?) of questions that are deleted by the questions owner are also removed without a trace? This has happened to me twice recenty, and it is rather annoying not to see the reasons why my contributions are gone. I also started to wonder if I had missed the question in some way when returning to the site, and used key word searches to maybe find it.
Since I've reached the "access to moderator tools" privilege, I can see questions that are deleted by moderators or by the community (under Review: Tools), but apparently this do not hold for questions deleted by the post owner. However, I suspect that "trused users" can see the questions I'm talking about. My suggestion for the future would be that all users that have "contributed" to a question should be able to see the deleted question, and a reason for why it has been deleted.
Granted, in both the recent cases I've witnessed, the questions had slight problems or lacked research. In the first case, the question was borderline off-topic (network analysis), but I thought that it was still a good contribution and the poster had clearly thought alot about the problem and included a nice background. The main problem here was probably that MathSe would be a better fit, and maybe that the original poster would be less likely to get a good answer at BioSE (which I pointed out in a comment). In the latter case (a question today about division of earthworms), I pointed out in a comment that it was based on a common myth, which probably led the poster to remove the question. However, for the general case, I don't think it is a good idea that the original poster can delete not only his/her own material (the question) but also everything else. Or have I misunderstood something? Is everything removed also if the question has a posted answer?
A also realize that this is potentially a bigger question for the entire Stack Exchange community, but I first want to see what users of BioSE think.