As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX FLIGHT NR 2190 AT 15,000' ON DESCENT HAD A RAPID DEPRESSURIZATION OF CABIN. ALL EMERGENCY PROCEDURES WERE FOLLOWED. UTILIZED OXYGEN. SUSPECT FORWARD OUTFLOW VALVE FAILURE AS NOISE CAME FROM COCKPIT LOWER SIDE. REPLACED BROKEN NUTPLATES WITH SOLID RIVETS ON FORWARD AND AFT PANELS ON LEFT SIDE OF AIRCRAFT. REPLACED SAFETY OUTFLOW VALVE. OPERATIONAL TEST GOOD. AIRCRAFT RETURNED TO SERVICE.