As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN)DURING PASSENGER DISEMBARKATION, SMOKE FUMES DETECTED IN CABIN WHILE APU RUNNING AND LEFT PACK ON. BOTH ENGINES GROUND RUN & BOTH PACKS OPERATED. SMOKE ONLY WAS EVIDENT WHEN LEFT PACK WAS OPERATED FROM APU. SUSPECT RESIDUE OF DE-ICEING FLUID INJECTED ACCIDENTLY.