As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED WITH THE SUPP A/C RUNNING THE CABIN BEGAN TO FILL WITH SMOKE. CREW TURNED OFF SUPP A/C SYSTEM AND EXITED THE AIRCRAFT. AFTER TEN MINUTES OR SO, THE SMOKE WAS GONE. FIRE DEPARTMENT SHOWED UP TO AIRCRAFT AS WELL. NO FURTHER INFORMATION AT THIS TIME.