As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CARGO COMPARTMENT FIRE INDICATION IN COCKPIT. DIVERTED TO GRR, LANDED WITHOUT PROBLEM. TURNED CARGO COMPARTMENT FIRE EXTINGUISHER AND BOTH ENGINE FIRE EXTINGUISHERS ON. TURNED ON EMERGENCY LIGHT, ELT AND PRESSURIZATION DUMP SWITCHES. MAINTENANCE REPLACED FIRE BOTTLES AND CARGO SMOKE DETECTOR, OPS CHECKS GOOD. RESET SWITCHES.