Late at night on Aug. 23, 1988, in Saint-Basile-Le-Grand, residents were awakened by explosions at a nearby warehouse that stored 500 barrels of oil laced with the toxin polychlorinated biphenyl (PCB). A large cloud of smoke spread out across 14 acres of the neighboring town, Saint-Bruno-De-Montarville, and emergency workers told residents to evacuate the area.