A321 captain reported a depleted oxygen system led to a diversion.

Attributes
ACN	1593090
Time
Date	201811
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	A321
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Component
Aircraft Component	Oxygen System/Crew
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

A routine check at cruise alt indicated crew oxygen pressure was zero. ATC was advised we would need to descend and divert. Dispatch was contacted and after a short discussion we agreed on diverting. ATC; flight attendant (flight attendants); passengers all notified; QRH; overweight landing procedures complied with followed by a normal approach landing rollout and taxi-in. Station operations did an outstanding job of taking care of our passengers in the middle of the night! Contract maintenance was unable to service our O2 bottle or complete an overweight landing inspection. Flt crew was released to hotel.

Original NASA ASRS Text

Title: A321 Captain reported a depleted oxygen system led to a diversion.

Narrative: A routine check at cruise alt indicated crew oxygen pressure was zero. ATC was advised we would need to descend and divert. Dispatch was contacted and after a short discussion we agreed on diverting. ATC; FA (Flight Attendants); passengers all notified; QRH; overweight landing procedures complied with followed by a normal approach landing rollout and taxi-in. Station operations did an outstanding job of taking care of our passengers in the middle of the night! Contract maintenance was unable to service our O2 bottle or complete an overweight landing inspection. Flt crew was released to hotel.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.