As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED WHILE CLIMBING THROUGH FL200 THE CABIN LOW PRESSURE LIGHT ILLUMINATED. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT DIVERTED. MAINT FOUND A TY-WRAP LODGED IN THE OUTFLOW VALVE. THE DEBRIS WAS REMOVED AND SUBSEQUENT OPERATIONAL CHECKS WERE SUCCESSFUL.