As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLE - THE CREW REPORTED A MOMENTARY APU FIRE MASTER WARNING IN FLIGHT DURING START. THE AIRCRAFT LANDED AT CLE WITHOUT INCIDENT WHERE MAINTENANCE INSPECTED THE APU, PERFORMED OPERATIONAL CHECKS WITH NO DEFECTS NOTED. THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.