Globe and Mail: Federal officials probing the Lac-Mégantic disaster are testing the chemical composition of crude oil carried by the runaway train as they seek to answer the crucial question of what triggered the unusual and devastating explosion after the derailment.
Transportation Safety Board investigators are collecting oil samples from each of the 72 rail cars that hurtled down a hill into the small Quebec town and ignited an enormous fireball that levelled more than 40 buildings and, as of the latest count,...