What was found
(CAN) ACFT EXPERIENCED A RAPID LOSS OF CABIN PRESSURIZATION ENROUTE WHILE OPERATING AT A CRUISING ALTITUDE OF FL240. THE CREW CONDUCTED AN EMERGENCY DESCENT AND REPORTED THAT THEY WERE NOT ABLE TO REGAIN ANY CONTROL AFTER FOLLOWING THE QRH PROCEDURE. EMERGENCY SERVICES RESPONDED UPON ARRIVAL OF THE ACFT TO PROVIDE MEDICAL SUPPORT TO A PASSENGER/S WHO EXPERIENCED ISSUES ASSOCIATED WITH THE DEPRESSURIZATION/DESCENT. INITIAL INVESTIGATION SHOWED CPC/OF VALVE DATA FAIL STATUS IN THE CDS. MAINTENANCE FOUND DUCT RUPTURED.