As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SIMULATED ETOPS WHILE AT YQX, A/C SUSTAINED RAPID DECOMPRESSION IN-FLIGHT AND DIVERTED TO YQX. MAINTENANCE FOUND MAIN CARGO DOOR SEAL BLOWN. REPLACED DOOR SEAL AND OPERATIONAL CHECK OF PRESSURIZATION SYSTEM NORMAL FOR BOTH SYS 1 AND SYS 2.