What was found
SFO - ACFT FAILED TO PRESSURIZE AFTER DEPARTURE. ACFT RETURNED TO STA WITHOUT INCIDENT. UPON INSPECTION OF ACFT AT GATE, CARGO DOOR HANDLE DISCOVERED UNSECURED. MAINTENANCE INSPECTED CARGO DOOR AND HANDLE, AND NO DEFECTS NOTED. CARGO DOOR OPERATION NORMAL (CARGO DOOR WARNING SYSTEM PREVIOUSLY DEFERRED PER MEL 52-70-1). PRESSURIZATION SYSTEM OPERATIONAL CHECK NORMAL ON GROUND. ACFT RETURNED TO SERVICE. (W)