What was found
SFO- FLIGHT 2524, AFTER TAKEOFF, DURING CLIMB RECEIVED A CABIN ALTITUDE MESSAGE. DIVERTED AIRCRAFT TO OAKLAND AND ACCOMPLISHED A UNEVENTFUL LANDING. MAINTENANCE FOUND THE AFT CARGO DOOR NOT PROPERLY CLOSED, AFT SECTION OF DOOR NOT SECURE. PERFORMED OPERATIONAL CHECK OF DOOR WITH NO DEFECTS FOUND. PERFORMED PRESSURIZATION CHECK WITH NO DEFECTS FOUND. AIRCRAFT RETURNED TO SERVICE WITH NO PARTS REPLACEMENTS.