As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STL - DURING DESCENT, SMOKE APPEARED IN CABIN WITH A HOT ODOR. TURNED OFF AIRFOIL ANTI-ICE AND SMOKE AND ODOR DISSIPATED. ACCOMPLISHED AIR CONDITIONING DUCT OIL CONTAMINATION CHECKS AND AIR CONDITIONING SYSTEM OPERATION CHECKED NORMAL. CHECK C-2D.