As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOWER CARGO FIRE LIGHT ILLUMINATED IN FLIGHT. ESTABLISHED EMERGENCY DESCENT TO SIOUX FALLS, SD. LIGHT WENT OUT WHILE DESCENDING. LANDED IN SIOUX FALLS WITH NO PROBLEMS. NO FIRE/SMOKE DETECTED BY SIOUX FALLS FIRE/RESCUE PERSONNEL. ABX ENGINEERING DOWNLOADED DATA FROM THE CCU. NO DISCREPANCIES NOTED. SYSTEM CHECKED GOOD IAW DC-9 MM CHAPTER 26.