As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, THE FORWARD CARGO COMPARTMENT NR 2 AND NR 4 SMOKE DETECTOR LIGHTS AND FORWARD CARGO FIRE LIGHT ILLUMINATED. FOLLOWED COM PROCEDURE AND PROCEEDED TO NEAREST AIRPORT (BIL) FOR AN UNEVENTFUL LANDING. BOTH FIRE BOTTLES RELEASED. REPLACED NR 2, 3 AND 4 SMOKE DETECTORS AND BOTH FIRE BOTTLES. OPERATIONAL CHECK GOOD.