As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAS - SMF - FLT 226 - CREW REPORTED DURING DESCENT TRIED TO START APU. APU FIRE WARNING HORN SOUNDED, CREW DISCHARGED FIRE BOTTLE, FIRE WARNING INDICATION EXTINGUISHED. THE CREW DECLARED AN EMERGENCY AND THE CABIN WAS PREPPED IN CASE FURTHER EMERGENCY ACTION WAS NECESSARY. THE LANDING WAS UNEVENTFUL AND THE AIRCRAFT TAXIED TO THE GATE. MX PLACED THE APU ON MEL. OPEN