What was found
AFTER DEPARTING HPN AND CLIMBING THROUGH APPROXIMATELY 9000-10000 FT THE CREW INDICATED THAT THEY FELT PRESSURE CHANGES IN THEIR EARS. THE CABIN PRESSURE VSI WAS FLUCTUATING, SHORTLY THEREAFTER IT INDICATED A FULL-RATE CABIN CLIMB, TOTAL DEPRESSURIZATION. THE CREW DECLARED AN EMERGENCY AND ARRESTED THE CLIMB, THEN BEGAN A DESCENT TO 9000 FT IN COORDINATION WITH ATC. THE CREW REQUESTED VECTORS TO LAND AND DID SO WITH NO FURTHER ISSUES. THE CAUSE OF THE PROBLEM, MECHANICAL DEFECT IS UNKNOWN AT THIS TIME.