[eudaemon]

It was your bog-standard disk crash as I understand it. Pros were (eventually) brought in for data recovery. But I also understand the backup for the wikis on that server (like mine, one of the dead ones) was on the same server, which doesn't sound like a very good plan. If a backup was stored elsewhere, the dead wikis would have been restored in a very short time. Lesson learned, I hope.

I got most all of my data restored, but there was a temporary problem of deleting and replacing files that the server programming thought still existed. That was fixed quickly.