As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LANDING, THE LEFT HYDRAULIC PRESSURE AND QUANTITY WENT TO ZERO. SHORTLY AFTER, THE CABIN BEGAN TO FILL WITH SMOKE. THE PACKS WHERE SHUT OFF AND THE SMOKE DISSIPATED. MAINTENANCE FOUND THE B-NUT LOOSE ON THE HYDRAULIC LINE TO THE LEFT ENGINE DRIVEN HYDRAULIC PUMP FILTER MODULE. MAINTENANCE SECURED THE LINE AND REPLACED THE PUMP AND PTU.