What was found
STRAIGHT LEVEL FLIGHT AT FL270 CREW RECEIVED AMBER AIR CONDITIONING FAIL LIGHT FOLLOWED BY A RAPID DECOMPRESSION. O2 MASK DEPLOYED, THEN RECEIVED CABIN LOW PRESS LIGHT. ACCOMPLISHED CHECKLIST PROCEDURES & DID NOT RESOLVE THE ISSUE. ACFT LANDED SAFELY AT THEIR DESTINATION. R & R LT & RT AIRFRAME PRSOV'S. FOUND LEAKING MAIN ENTRY DOOR SEAL, REPLACED DOOR SEAL. LEAK & OPERATIONS CHECKED GOOD.