What was found
AT 27,000 FT IN CRUISE, CABIN STARTED CLIMBING AT 7,200 FPM EMERGENCY DESCENT INITIATED. ALL CHECKLIST COMPLIED WITH. AT 7,000 FT CABIN CONTROL WAS RE-ESTABLISHED. FOUND C-2 CARGO UPPER DOOR SEAL MISSING. REPLACED TOP SECTION FROM TOP CORNER TO TOP CORNER. PRESSURIZED A/C, OPN NORMAL.