As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FIRE IN THE LEFT AFT LAV UNDER THE SEAT SHROUD. LIQUID LEVEL SENSOR FAILED INTERNALLY CAUSING A FIRE THAT DAMAGED THE SENSOR ITSELF ALONG WITH THE TOILET SEAT SHROUD AND A NEARBY AIR VENT. REPLACED LIQUID LEVEL SENSOR, TOILET SHROUD, AND VENT ASSEMBLY AND RETURNED LAVATORY TO SERVICE.