As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ARRIVING, FLIGHT ATTENDANTS REPORTED FUMES AND AN ODOR IN REAR OF CABIN. APU WAS IMMEDIATELY TURNED OFF AND APU SHUT DOWN. AFTER ALL PASSEMGERS DEPLANED APU WAS RESTARTED AND AIR WAS TURNED ON. MAINTENANCE SUSPECT APU AIR COOLING FAN BAD. MAINTENANCE REPLACED APU AIR COOLING FAN PER AMM 49-52-51. ACCOMPLISHED JOB CARDS 26L00021001 CABIN AIR QUALITY, 26L00021002 APU SMELL IN CABIN, 26L31049009 CLEAN APU LOAD COMPRESSOR, AND 26L00021004 DECONTAMINATION OF THE ENVIRONMENTAL CONTROL SYSTEM. AIRCRAFT WAS GROUNDED.