What was found
AIRCRAFT WAS IN ROUTE TO GRB FROM LAN. SHORTLY AFTER CLIMB OUT AND AIRCRAFT WAS LEVEL IN CRUISE AT 16,000FT PILOT HEARD A LOUD POP AND CABIN DEPRESSURIZED. PILOT PERFORMED EMERGENCY DESCENT AND DIVERTED TO GRR AND PASSENGERS WERE PICKED UP AND FLOWN TO THEIR DESTINATION. MAINTENANCE INSPECTED THE CABIN PRESSURIZATION SYSTEM AND FOUND A FLEXIBLE DUCT HAS COME LOOSE AND SEPARATED FROM ONE END OF THE SUPPLY DUCT. MAINTENANCE INSPECTED THE DUCT, FLEXIBLE DUCT AND CLAMP AND FOUND ALL THREE TO BE SERVICEABLE. MAINTENANCE RESECURED THE FLEXIBLE DUCT TO SUPPLY DUCT AND TIGHTENED THE CLAMP AS REQUIRED. INSPECTED REMAINING CLAMPS FOR TIGHTNESS AND SECURITY. TESTED THE PRESSURIZATION SYSTEM AND CHECKED NORMAL. RELEASED AIRCRAFT RETURNED THE BASE.