As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CREW GOT INTERMITTENT CARGO SMOKE INDICATIONS. DECISION WAS MADE TO DISCHARGE FIRE EXTINGUISHERS. UPON ARRIVAL, IT WAS DISCOVERED THERE HAD BEEN NO FIRE. AIRCRAFT OPERATED ON MEL, UNTIL FIRE EXTINGUISHERS COULD BE REPLACED. NO OTHER MAINTENANCE PERFORMED PRIOR TO RETURN TO SERVICE.