What was found
PERFORMED AN IFSD AND AN ATB, DUE TO A REPORTED FIRE WARNING ON THE NR 2 ENGINE. AFTER REDUCING THE THROTTLES, THE WARNING EXTINGUISHED. VIBRATIONS WERE REPORTED IN THE AFT CABIN. IAW QRH, THE NR 2 ENGINE WAS SHUTDOWN. THE NR 2 ENGINE FIRE BOTTLE WAS DISCHARGED. MAINTENANCE FOUND THE NR 2 ENGINE 13TH STAGE DUCT BLOWN WITH DAMAGE TO THE 8TH STAGE DUCT, THE FIREWALL, AND A WIRING HARNESS. THE EGT IAW THE FLIGHT DATA RECORDER HAD REACHED 679 DEG. MAINTENANCE REPLACED BOTH NR 1 AND THE NR 2 ENGINES. THE FIRE BOTTLE WAS REPLACED.