Fortunatley I had some family running by home at 3PM. I called home, and talked them through a reboot.
The machine had rebooted and was sitting at the login screen. I do not know if this was a spontaneous sytem reboot of the server machine, or if we had a power failure that reset everything. (I didn't think to ask if the microwave clock had reset to noon.....)
Hopefully it was nothing serious, and the server will stay up until I get home.
-Herr Burt