What was found
AIRCRAFT GROUNDED: AN EMERGENCY DECLARED & ACFT RETURNED TO MIA DUE TO FLT CREW REPORTED THAT AT V1, LT ENG FIRE FAULT CAME ON TWICE. FLT CREW ACCOMP CHKLST & SHUT ENGINE DOWN. AFTER ENGINE SHUT DOWN, THE FAULT WENT AWAY. FLT CREW INFORMED BY THE FLIGHT ATTENDANTS, THERE WAS NO SMOKE OR FIRE SO FLT CREW DID NOT BLOW SQUIBS. ACFT RAN ON SINGLE ENG FOR ABOUT 20 MINS & LANDED SAFELY IN MIA WHERE IT TAXIED TO GATE UNDER ITS OWN POWER. MAINT FOUND BLOWN DUCT ON INBD HALF OF ENG 1 & REPLACED ENGINE IAW JOB CARD 26L40071001.