As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED AN OVERBOARD COOL FAIL MASTER CAUTION EN ROUTE FROM CLT TO BHM. CABIN ALTITUDE STARTED CLIMBING AND AIRCRAFT DEPRESSURIZED. AIRCRAFT DIVERTED TO ATL AND LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT THE AIRCRAFT, REMOVED AND REPLACED THE PASSENGER DOOR WARNING SYSTEM MICRO SWITCH AND PERFORMED CHECKS USING THE AIRCRAFT MAINTENANCE MANUAL. AIRCRAFT WAS RELEASED FOR SERVICE.