As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - FLIGHT 2276 - CARGO DOOR OPEN INDICATION AT ROTATION. RETURNED TO THE FIELD AND ACCOMPLISHED A OVERWEIGHT LANDING OF 62,200 LBS ACCORDING TO THE FMS. DESCENT RATE WAS 100 TO 200 FPM. MAINTENANCE ACCOMPLISHED A OVERWEIGHT LANDING INSPECTION WITH NO DEFECTS NOTED. PERFORMED OPERATIONAL TEST OF THE CARGO DOOR WITH NO DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.