What was found
RAPID DEPRESSURIZATION 33,000 FEET, SOURCE UNKNOWN. LOUD BANG, UNABLE TO REGAIN CONTROL OF PRESSURIZATION. ABLE TO HOLD CABIN ALTITUDE TO 7,000 AT A/C ALTITUDE OF 14,000, RETURNED TO LAX. FOUND AFT PRESSURE P-DOME CHORD ANGLE THAT ATTACHED P-DOME TO FUSELAGE STRUCTURE FRACTURED BETWEEN STRINGER NR 10 AND NR 55. CRACK LENGTH WAS APPROXIMATELY 12 FEET, UNDER INVESTIGATION.