As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW EXPERIENCED A STRONG FIRE/SMOKE SMELL DESCENDING THROUGH FL180. FLIGHT CREW SHUT LEFT PACK OFF PER CHECKLIST, SMELL WENT AWAY. TROUBLESHOOTING FOUND THE LEFT HAND AIR CYCLE MACHINE SEIZED. A SERVICEABLE UNIT WAS INSTALLED WITH NOT FURTHER ANOMALIES NOTED.