As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OXYGEN LOW PRESSURE CAUTION MESSAGE APPEARED DURING DECENT. IAW QRH DIRECTION, OXYGEN PRESSURE CONTINUED TO DECREASE, DURING ENTRY OF AIRCRAFT, NOTICED A LOUD HISSING COMING FROM FO'S OXYGEN MASK. NOTED MASK LEAKING SIGNIFICANTLY, REMOVED AND REPLACED THE MASK IAW AMM 35-11-12 AND SERVICED THE OXYGEN SYS TO 1850 PSI IAW AMM 12-16-35. NO FURTHER LEAKS NOTED AT THIS TIME. OPS CHECKED GOOD.