LAC-MEGANTIC, Quebec (AP) — It was surely the most festive spot in town as a Friday night turned into a Saturday morning at the Musi-Cafe – a full house, live music, plenty of beer and nachos to animate long-time friends.Among the dozens enjoying themselves in the pub was a sizable contingent of the Lafontaine clan, celebrating the 40th birthday of a daughter of prominent local businessman Raymond Lafontaine.Four days later – having lost a son and two daughters-in-law who were among the revelers – Lafontaine stood near a throng of reporters on a street near the town center, watching them pepper an American railroad executive with questions.Any possible culpability on the part of the railway remains to be determined. But it is fact that an unmanned Montreal, Maine and Atlantic freight train with 72 cars carrying shale oil turned into a runaway death machine – rolling away from its overnight parking spot, barreling for miles down an incline in the dark of night, derailing in the heart of Lac-Megantic at 1:14 a.m. on July 6, and snuffing out 50 lives when a series of explosions set off a ferocious fire.Gilles Fluet, a 65-year-old retiree who used to work at a door-making factory, left the Musi-Cafe just moments before the first explosion and saw the train go by.“It was moving at a hellish speed ... no lights, no signals, nothing at all,” he said. “There was no warning.