As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAINTENANCE REPORTED SMELLING FUMES WHILE INSIDE THE COCKPIT AFTER TROUBLESHOOTING THE APU AND THE APU RUNNING. MAINTENANCE INVESTIGATED AND FOUND THE APU ON FIRE. FIRE WAS EXTINGUISHED USING THE APU FIRE BOTTLE. MAINTENANCE INSPECTED AND FOUND A FUEL LEAK IN THE APU COMPARTMENT. THE APU WAS INSPECTED AND DEFERRED. AIRCRAFT WAS RELEASED FOR SERVICE.