As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 APU GENERATOR BEARING MSG DURING T/S CHECK, BURNING SMELL INSIDE CABIN SUSPECT APU FIRE. FLT CREW FOLLOW QRH AND FIRE HANDLE PULLED AND FIRE BOTTLE DISCHARGED. APU COMPARTMENT CHECKED AND FOUND HEATING DAMAGE. NR 1 GEN DISINTEGRATED CAUSING DEBRIS IMPACT DAMAGE.