Is it possible for a post to just vanish for no reason?

This has happened at the forum I moderate at. We are fairly certain it was not deleted by any of the moderators or administrators.

maybe the poster deleted it , have you aked them?

this is like saying.. is it possible to open a door without touching it?
there is always a culprit in every crime

check admin panel> general >security then the moderation!
check who deleted the post.

not sure if it works though on ordinary members