I sat down in the control room to find that ETMX and PRM's watchdogs had been tripped. I don't know how long they've been crazy, but there was a big something that showed up in the seismometers around 16:30UTC, or ~11:30 this morning. I don't find any significant earthquakes on the USGS site for that time though, so it might be more local, i.e. work next door or trucks or whatever.
I take back the suggestion that it was that seismic event. Clearly the PRM and the ETMX were kicked at different times, neither of which is the same as the seismic action. Mystery. You can see they have been ringing down for a while though, which is neat.