As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - FLIGHT 2187, THE CREW REPORTED A CARGO SMOKE WARNING DURING CRUISE. THE CREW DISCHARGED BOTH BOTTLES AS A PRECAUTION, AND RETURNED TO IAH, LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE BAGGAGE COMPARTMENT WITH NO DEFECTS NOTED. REMOVED AND REPLACED THE FWD SMOKE DETECTOR, OPERATIONALLY TESTED WITH NO DEFECTS. AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.