As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HLN - ON FLIGHT 2419 (BIL-SEA) FORWARD CARGO DOOR WARNING CAME ON. AIRCRAFT DIVERTED TO HLN AND ACCOMPLISHED A UNEVENTFUL LANDING. NO CFR EQUIPMENT WAS CALLED. MAINTENANCE FOUND THE HANDLE/SHAFT OF THE DOOR NOT SEATED. SEATED THE SHAFT/HANDLE, LIGHT WENT OUT. CYCLED DOOR, CHECKS OK. AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.