Shortly before 1 a.m. on July 6, 2013, an unattended Montreal, Maine & Atlantic Railway freight train, MMA-002, rolled away from the village of Nantes, Quebec, gathered speed down the grade for some seven miles, and derailed in the centre of Lac-Mégantic at about 65 mph (105 km/h). The train carried 72 tank cars of crude oil; 63 of them derailed, and about six million litres of oil spilled and ignited. The fires and explosions destroyed much of the downtown core — 40 buildings and 53 vehicles — and killed 47 people.
The train had been parked for the night on the main track at Nantes, on a descending grade, with a single-person crew. Its engineer applied seven hand brakes, although his company’s own rules called for at least nine for this train and the Transportation Safety Board of Canada later calculated that 17 to 26 would have been needed on their own; his effectiveness test was made with the locomotive air brakes still applied, masking how little the hand brakes held. The lead locomotive, already in mechanical trouble, was left running to maintain air pressure. At about 11:50 p.m. it caught fire, and firefighters shut it down. With every locomotive off, the air brakes leaked away at about one pound per minute — too slowly to trigger an automatic application — until the train began to roll.
The cargo made the derailment catastrophic. The 7.7 million litres of crude oil came from the Bakken formation of North Dakota and was carried in Class 111 (DOT-111) tank cars built to an older standard, without jackets, full head shields or thermal protection; almost every derailed car was breached. The oil had been classified as Packing Group III, the least hazardous grade, but TSB laboratory testing found it behaved as Packing Group II, with a flash point below −35°C — which, the Board found, helps explain why it ignited so quickly and burned so fiercely.
In its report R13D0054 (August 2014), the TSB identified 18 causes and contributing factors and stated plainly that the accident was “not caused by one single person, action or organization.” The railway’s safety culture was weak and its safety management system ineffective; Transport Canada had known for years that the railway was an elevated risk, repeatedly found the same securement, training and track deficiencies, and, in the Board’s words, “did not provide adequate regulatory oversight.” The Board issued five recommendations, covering tank-car standards, route planning, emergency response plans, additional physical defences against runaways, and effective — not merely paper — safety management systems.
Reform came quickly. Within weeks, emergency directives barred leaving dangerous-goods trains unattended on main tracks and required minimum two-person crews; crude oil had to be properly tested and classified; and new securement rules set a standard hand-brake chart and required additional physical defences, later written permanently into the Canadian Rail Operating Rules. The oldest DOT-111 cars were pulled from crude service, legacy tank cars were phased out of crude oil transport entirely by November 1, 2016, and a new TC-117 standard — thicker steel, jacket, thermal protection and full head shields — became the required design.
Download TSB Report R13D0054 (3 MB file)