As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EXCESSIVE AMOUNT OF SMOKE CAME FROM APU TAIL PIPE. SUPPLEMENTAL DATA UPDATE, FOUND TURBINE ROLLER BEARING FAILED. LOSS OF OIL AND LOW OIL PRESSURE DUE TO BEARING FAILED RESULTED IN FLASH COMBUSTION AND HEAVY SMOKE. REPLACED THE BEARING.