On September 2, 1998, Swissair Flight 111, an MD-11 flying from New York to Geneva, crashed into the Atlantic near Peggy's Cove, Nova Scotia. All aboard died. The crew had reported smoke in the cockpit about twenty minutes before impact and was diverting to Halifax when contact was lost.
Investigators found that the fire began with arcing in the wiring of the in-flight entertainment network above the ceiling of the forward cabin, which then ignited the metallised insulation blankets lining the fuselage. The system had been added to the aircraft the previous year. Those blankets met the flammability standard that applied when new, but the material aged badly in service and burned fast once it caught.
The cockpit voice and flight data recorders stopped about six minutes after the first smell of smoke, presumably because the fire cut power to them. That gap left a partial record and forced a five-year inquiry that cost around 57 million Canadian dollars, the most expensive in the country's history.
The findings changed aircraft certification. Flammability testing was tightened, wiring near passenger systems was re-examined, and metallised mylar insulation was withdrawn from use. Recovery crews lifted almost the whole airframe off the seabed. The wreck was recovered. The site is now a protected place under Canadian law.