As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MCI - DURING MAINTENANCE INSPECTION, THE AFT EXTERIOR EMERGENCY LIGHTS WERE FOUND TO BE INOPERATIVE. MAINTENANCE REMOVED AND REPLACED THE NUMBER FOUR EMERGENCY LIGHT BATTERY, OPERATIONALLY CHECKED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.