On January 7, 2013, about 1021 eastern standard time, smoke was discovered by cleaning personnel in the aft cabin of a Japan Airlines (JAL) Boeing 787-8, JA829J, which was parked at a gate at General Edward Lawrence Logan International Airport (BOS), Boston, Massachusetts. About the same time, a maintenance manager in the cockpit observed that the auxiliary power unit (APU) had automatically shut down.2 Shortly afterward, a mechanic opened the aft electronic equipment bay (E/E bay) and found heavy smoke coming from the lid of the APU battery case and a fire with two distinct flames at the electrical connector on the front of the case.3 None of the 183 passengers and 11 crewmembers were aboard the airplane at the time, and none of the maintenance or cleaning personnel aboard the airplane was injured. Aircraft rescue and firefighting (ARFF) personnel responded, and one firefighter received minor injuries. The airplane had arrived from Narita International Airport (NRT), Narita, Japan, as a regularly scheduled passenger flight operated as JAL flight 008 and conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 129. The captain of JAL flight 008 reported that the APU was turned on about 30 to 40 min before the airplane left the gate at NRT (about 0247Z) and was shut down after the engines started.4 He stated that the flight, which departed NRT about 0304Z, was uneventful except for occasional moderate turbulence about 6.5 to 7 hours into the flight. Flight data recorder (FDR) data showed that the airplane touched down at BOS at 1000:24 and that the APU was started at 1004:10 while the airplane was taxied to the gate. The captain indicated that the APU operated normally. FDR data also showed that the airplane was parked at the gate with the parking brake set and both engines shut down by 1006:54. The maintenance manager (the JAL director of aircraft maintenance and engineering at BOS) reported that the passengers had deplaned by 1015 and that the flight and cabin crewmembers had deplaned by 1020, at which time he and the cabin cleaning crew had entered the airplane. Shortly afterward, a member of the cleaning crew told the maintenance manager, who was in the cockpit, about "an electrical burning smell and smoke in the aft cabin." The maintenance manager then observed a loss of power to systems powered by the APU and realized that the APU had automatically shut down. After confirming that the airplane's electrical power systems were off, the maintenance manager turned the main and APU battery switches to the "off" position. FDR data showed that the APU battery failed at 1021:15 and that the APU shut down at 1021:37, which was also when the APU controller lost power. A JAL mechanic in the aft cabin at the time reported that, when the airplane lost power, he went to the cockpit and learned that the APU had shut down. The mechanic then went back to the aft cabin and saw and smelled smoke. A JAL station manager arrived at the airplane and reported that, when he went into the cabin (through the door where the passenger boarding bridge is attached), he saw "intense" smoke that was concentrated 10 ft aft of the door. The turnaround coordinator for JAL flights 008 and 007,5 who had also entered the aft cabin and observed the smoke, described the smoke as "caustic smelling." The mechanic notified the maintenance manager about the smoke, and the maintenance manager asked the mechanic to check the aft E/E bay. The mechanic found heavy smoke and flames in the compartment coming from the lid of the APU battery case. The mechanic reported that he used a dry chemical fire extinguisher (located at the base of the passenger boarding bridge) to attempt to put out the fire but that the smoke and flames did not stop.