server not found…HELP!

suddenly, I can’t access my wordpress page. every time i enter the address it comes up with SERVER NOT FOUND; firefox cannot find the server at balkansproject.org (my webpage). none of the other people working on the project can access it either. what steps do i take from here? I have to have this thing up and running by fri morning (may 2nd) for a meeting. any help you can give would be greatly appreciated!!