What was found
A/C EXPERIENCED A FAILURE OF THE OUTER PANEL OF THE CO-PILOTS SIDE REAR WINDOW WHILE PASSING THRU FL250 & WITHIN MOMENTS OF CHECKING THE CHECKLIST THE WINDOW HAD A COMPLETE FAILURE FOLLOWED BY DECOMPRESSION. CREW EXECUTED AN EMERGENCY DESENT PROCEDURES & DECLARED AN EMERGENCY. DUE TO EXTREME NOISE IN COCKPIT BROADCASTED INTENTIONS WITH ATC IN THE BLIND. AFTER DECENDING THROUGH 14000 AND SLOWING AIRCRAFT COMMUNICATION WITH ATC WAS RESTORED. LAND KACY WITH NO FURTHER ISSUES. EMERGENCY AND MEDICAL PERSONNEL MET THE A/C & ASSISTED WITH PASSENGER & CREW NEEDS. WHILE MX TECH WAS INSPECTING WINDOW AREA IT WAS NOTED THAT THE HARDWARE SECURING THE WINDSHIELD ALONG WITH ALL THE OTHER WINDSHIELDS WAS INCORRECT PER THE IPC. ALL SIDE WINDOWS ARE ORIGINAL AND WERE INSTALLED AT THE FACTORY DURING BUILD.