Looking at the plots of this event there is about a 4-5 sec delay between the lock loss and the first reponse of the vacuum gauges at EY.

The EY transmon shows a decay of the intra cavity power over about 100-200 ms, which is normal. There was nothing significant on PEM channels.There is no obvious resean why this lock loss would have caused a vacuum spike.

The delay between EY and MY is about 8 minutes.

Christmas Lockloss # 1

There was a Lockloss from Observing last night that was followed by an increase in pressure in End station Y and Mid station Y. But not in the Corner station.
https://ldas-jobs.ligo-wa.caltech.edu/~lockloss/index.cgi?event=1419158677

Out of an abundance of caution of melting things in the EY chamber, or an overactive imagination, I Held us in Check_Violins_Before PowerUp and called Daniel to determine if I should continue powering up the IFO.
He asked if the fast shutter, shuttered.
Yes, the Fast Shutter Shuttered.
Then he mentioned checking the Circulating Power in the Arms.
ndsope showing both the Fast shutter pop up and the circulating power.

He also checked the microphones at EY and didn't see anything at that time.

I checked the ground motion  and didn't see anything that stood out as a major event.
 

After Speaking with Daniel, My Fear of accidentally melting something were resolved. So I started to power up beyond 10 Watts.  Eventually reaching NLN.
 

It seems that we may have lost an ion pump, or there was glitch related to an ion pump controller, this pump is located at Y2-8, near the end station.  Heading to the site, be there sometime around 4.

Attached is a trend for most of the relatable signals at Y-End, the glitch is first noticed at the gauge located at Y2-9, color red, then the IP controller signal, also in red.