As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4920, DURING DESCENT CREW RECEIVED BAGGAGE FIRE WARN MESSAGE. CREW FOLLOWED AOM AND BLEW BOTTLES AND F/O INSPECTED AND FOUND NO FIRE. EMERGENCY DECLARED AND LANDED SAFELY IN YUL. INSPECTED CARGO AND NO EVIDENCE OF FIRE NOTED. ISSUED MEL 26-03 AND 26-09. AIRCRAFT REMOVED FROM SERVICE. REMOVED AND REPLACED CARGO FIRE BOTTLES. NO EVIDENCE OF SMOKE. PERFORMED OPERATIONAL CHECKS ON BAG SMOKE SYSTEM AND COULD FIND ANY FAULTS. AIRCRAFT RETURNED TO SERVICE.