As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD NOISE & RUSH OF AIR IN AFT GALLEY AREA RT SIDE OVERHEAD. BLOCK RETURN. FOUND PORTABLE OXYGEN BOTTLE IN AFT CABIN POSITION TO HAVE SUDDENLY DEPRESSURIZED TO ZERO PSI. REPLACED AFT PORTABLE OXYGEN BOTTLE IAW AMM 35-32-42 PAGE BLOCK 401. FLIGHT ATTENDANT VERIFIED PORTABLE OXYGEN BOTTLE WAS FULL DURING PREFLIGHT CHECK.