Just noting that this kind of thing can happen when platforms are in different states. Something caused large-ish high frequency ground motion in a short burst this afternoon and tripped HAM7 and ITMY, because those chambers were damped, but not any of the other chambers because they had high gain isolation loops running, or were already tripped/locked. What ever it happened was louder at HAM7, than the ITMs, as shown in the top left of the attached plot. Because the motion was high frequency, where the isolation loops had enough gain to keep the ISI seismometers from saturating, only HAM7 and ITMY tripped because their isolation loops were off, and damping only engaged. And the event was small enough to not saturate the actuators.