As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT 10TH STAGE FAILED CLOSED IN FLIGHT, UNABLE TO PROVIDE PRESSURE TO SINGLE PACK. (MOC NOTE RH PACK ON MEL) C/W IAC AND QRH FOR EMER DECENT. PASSENGER OXYGEN MASKS DEPLOYED, ON COMMAND. ISO VALVE FAILED TO OPEN WHEN COMMANDED. EMERGENCY DECLAIRED. AIRCRAFT REMOVED FROM SERVICE. INSPECTED AND FOUND 10TH STAGE ISOL VALVE CANON PLUG LOOSE. RECESURED CONNECTOR PLUG IAW AWA SUP 19-037. R+R L 10TH STAGE SOV IAW AWA AMM 36-11-04 AND AWAC SUP 19-036. OPS CHECK GOOD. LEAK CHECK GOOD.