As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SDF - INFLIGHT CMH-DFW. CREW REPORTED AUXILIARY POWER UNIT FAILED IN FLIGHT WITH RIGHT ENGINE DRIVEN GENERATOR PLACARD PER MEL REF 24-01B. EMERGENCY DECLARED DIVERTED SDF LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED RIGHT CONSTANT SPEED DRIVE GENERATOR. THE APU WAS PLACARD PER MEL / REFERENCE 49-01. SYSTEM GROUND CHECK NORMAL OPERATION.