As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 4125 - CARGO SMOKE LIGHT CAME ON IN FLIGHT. DISCHARGED BOTH FIRE BOTTLES AND RETURNED TO FIELD. AIRCRAFT HAD NORMAL LANDING. INSPECTED SYSTEM AND PERFORMED OPS CHECKS. FOUND BLEED DUCT LINE LOOSE IN LEFT SIDE OF CARGO BAY. CORRECTED AND PERFORMED OPS CHECK OF SYSTEM IAW AMM 36-11-09. REMOVED AND REPLACED BOTH FIRE BOTTLES IN CARGO BAY. OPS CHECK GOOD IAW AMM 26-15-00. AIRCRAFT RETURNED TO SERVICE. (M)