The Webmaster has to leave for class, so nothing is done until the next day. The server refuses to reboot. We try that disk in other machines, and other disks in that machine.
All signs point to a failed disk.
We borrow a PC from the company where one of us works and begin work on a temporary server which will at least let people know what's going on. All mail is being refused. We have backup tapes, but they're many weeks old. The crashed disk is being sent off to a data recovery service to see what can be salvaged. Your humble Webmaster stepped in a pile of slippery tree seeds, those little propeller-looking thingies, fell, and broke every bone in his body.