As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH, SMOKE ACCUMULATED FROM SEAT BOX UNDER SEAT 32B. FLIGHT CREW DECLARED EMERGENCY AND RAISED CABIN ALTITUDE TO AID IN SMOKE REMOVAL. AIRCRAFT LANDED, TAXIED TO GATE, AND DEPARTED PASSENGERS WITHOUT INCIDENT. MAINTENANCE REPLACED SEAT BOX, OPERATIONAL CHECK OK.