As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU GENERATOR FAILED ON GROUND. COULD NOT RESET. FOUND THE APU GENERATOR AND ITS MOUNTAING PAD TO BE DAMAGED FROM EXCESSIVE HEAT. FOUND APU GENERATOR CATASTROPHICALLY FAILED AND DEPARTED FROM APU GEARBOX. REMOVED APU. INSTALLED APU GEN MOUNTING PLATE & GENERATOR ONTO APU. NEW APU GEN INSTALLED IAW MM 24-32-00.