As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO LAX DUE TO A FAILED APU. *S/D* THE APU FAILED DUE TO A BLOWN DUCT. THE MANUFACTURER HAS REVISED THE WELDING AND REPAIR PROCESS TO PREVENT ANY RUPTURES ALONG WELDED SEAMS. THE APU BLEED TEE DUCT AND PACKING WERE REPLACED. OPERATIONS CHECK NORMAL AND LEAK CHECKED OK.