As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) A DEPRESSURIZATION OCCURRED AT 21000 , ABNORMAL PROCEDURE CARRIED PER QRH. LOUD NOISE HEARD IN FLIGHT DECK DURING APPROACH. FOUND NR 2 WATER SEPARATOR DUCT SEPARATED FROM WATER SEPARATOR. FURTHER INSPECTION REVEALED A LARGE CRACK ON THE INLET FLANGE OF THE WATER SEPARATOR. MTCE REPLACED THE WATER SEPARATOR IAW AMM 21-51-31 AND ALSO REPLACED PACK NR 2 TURBINE OULET DUCT IAW AMM 20-21-05. LEAK CHECKS CARRIED OUT SERVICEABLE.