As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APU START ATTEMPT APU STARTER CAUGHT ON FIRE. PULLED CBS B-22 AND U39. FOUND HOLE BURNED IN STARTER. REMOVED AND REPLACED APU STARTER PER AMM 49-44. R&R RELAY R2-63 AND R5-792 PER WDM 49-41-00. APU OK FOR SVC. ALL CBS PUSHED IN.