What was found
LGA - FLT 1084 - EN ROUTE YYZ-LGA - APU FIRE AND AUTO SHUTDOWN DISCHARGED AGEN DURING IN FLIGHT. LANDED LGA WITHOUT FURTHER INCIDENT. REPLACED APU FIRE DETECTION CONTROL UNIT FIRE WARNING. REPLACED APU FIRE BOTTLE, APU FUEL SOLENOID IGNITER BOX, AND BOTH IGNITER PLUGS. ACCOMPLISHED OPERATION AND LEAK CHECK OF APU. CHECKED APU AND TAIL COMPARTMENT WITH BOTH ENGINES AT HIGH POWER. NO LEAKS DETECTED. INSPECTED APU ENCLOSURE, NO FIRE DAMAGE NOTED. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)