What was found
OKC - FLIGHT 3453, THE CREW REPORTED AN ENGINE NR 1 INFLIGHT FAILURE, LOUD BANG FOLLOWED BY UNCOMMANDED SHUTDOWN. THE AIRCRAFT RETURNED TO OKC WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE NUMBER ONE ENGINE, OPERATIONALLY CHECKED WITHOUT DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.