At 11:34 UTC, I heard a sustained alarm tone near the door of the control room. I tracked it down to the fire system panel in the Computer User's Room. Other than the tone, I noticed that the "System Trouble" light was blinking. I'll call Bubba when it get closer to normal waking hours.
Seems to have fixed itself as it is no longer alarming.
The alarm stopped for an hour or so, but has since started again. I'll call Bubba now.