As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NOTICED AT ALTITUDE THAT CREW OXYGEN PSI WAS 250. IT CONTINUED TO DECREASE, DESCENDED AND DIVERTED. EMERGENCY DECLARED. REPLACED BOTH THE CAPTAINS AND SECOND OBSERVERS OXYGEN MASKS IAWTSM 35-10-00. AMM 35-12-41. MASKS FAULTY. PERFORMED LEAK CHECK. NO LEAKS NOTED