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Rail transportation safety investigation R13D0054

The TSB has completed this investigation. The report was published on 19 August 2014.

Table of contents

Runaway and main-track derailment

Montreal, Maine & Atlantic Railway
Freight Train MMA-002
Mile 0.23, Sherbrooke Subdivision
Lac-Mégantic, Quebec

View final report

The occurrence

On , shortly before 0100 Eastern Daylight Time, eastward Montreal, Maine & Atlantic Railway freight train MMA-002, which was parked unattended for the night at Nantes, Quebec, started to roll. The train travelled approximately 7.2 miles, reaching a speed of 65 mph. At around 0115, when MMA-002 approached the centre of the town of Lac-Mégantic, Quebec, 63 tank cars carrying petroleum crude oil (UN 1267) and 2 box cars derailed. About 6 million litres of petroleum crude oil spilled. There were fires and explosions, which destroyed 40 buildings, 53 vehicles, and the railway tracks at the west end of Megantic Yard. Forty-seven people were fatally injured. There was environmental contamination of the downtown area and of the adjacent river and lake.

Read the executive summary

Safety Communications



TSB Recommendation R14-05: Transport Canada must take a more hands-on role when it comes to railways' safety management systems—making sure not just that they exist, but that they are working and that they are effective.


TSB Recommendation R14-04: Canadian railways must put in place additional physical defences to prevent runaways.


TSB Recommendation R14-03: Requirements for emergency response assistance plans.


TSB Recommendation R14-02: Route planning and analysis for trains carrying dangerous goods


TSB Recommendation R14-01: Vulnerability of Class 111 tank cars to sustain damage.


Letter from the TSB to the Honourable Lisa Raitt, P.C., M.P., Minister of Transport, and Ms. Cynthia L. Quarterman, Administrator, U.S. Pipeline and Hazardous Materials Safety Administration, dated 23 January 2014 making TSB recommendations R14-01, R14-02, and 14-03.

Safety advisories


Letter to Transport Canada on adequacy of short line railway training


Letter to Transport Canada on monitoring program for the classification of mined gases and liquids


Letter to Transport Canada on the determination of petroleum crude oil properties for safe transportation


Letter to the Pipeline and Hazardous Materials Safety Administration on the determination of petroleum crude oil properties for safe transportation


Letter to Transport Canada on the securement of unattended locomotives


Letter to Transport Canada on the securement of equipment and trains left unattended

(See also the safety advisory letter to Transport Canada arising from Railway Investigation R13T0060 on the operating lever design for tank car bottom outlet valves on Class 111 tank cars. The letter was sent to Transport Canada on 26 November 2013.)

Other correspondence

Media materials

News releases


TSB identifies systemic problems leading to Lac-Mégantic train accident and calls for additional safety defences to improve rail safety
Read the news release


Statement by Wendy A. Tadros, Chair, Transportation Safety Board of Canada, on the anniversary of the Lac-Mégantic train accident
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Strong first steps taken on TSB recommendations in Lac-Mégantic investigation
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TSB releases analysis of petroleum crude oil samples from train accident in Lac-Mégantic, Quebec
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TSB and NTSB call on Canadian and U.S. regulators to improve the safe transportation of crude oil by rail
Read the news release


TSB calls on Canadian and U.S. regulators to ensure properties of dangerous goods are accurately determined and documented for safe transportation
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Lac-Mégantic update: On-site operations wrapping up, ongoing investigation remains a top priority
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Lac-Mégantic update: Immediate safety issues identified
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Lac-Mégantic update
Read the news release


Speeches and presentations


Release of the Railway Investigation Report R13D0054
Wendy A. Tadros
Chair, Transportation Safety Board of Canada

Deployment notice


Transportation Safety Board of Canada deploys investigators to rail accident in Lac Megantic, Quebec

The Transportation Safety Board of Canada (TSB) is deploying investigators to the site of a rail accident in Lac Megantic, Quebec. A unit train carrying petroleum crude oil operated by Montreal Maine and Atlantic Railway derailed numerous cars. The TSB will gather information and assess the occurrence.

Blog post


In the Heart of a Tragedy: A Day in the Life of the Lac-Mégantic Investigator-in-Charge
Read the blog post

Video and audio materials

Audio clips


TSB Chair, Wendy Tadros, speaks about the TSB investigation into the accident in Lac-Mégantic
Download and listen to the audio clips

Video clips


News conference, Tuesday, 19 August 2014, 10:30 AM EDT, Lac-Mégantic, Quebec
Watch the news conference



Sequence of events in the Lac-Mégantic derailment and fire
Watch the animation


Damage to a Class 111 tank car in the Lac-Mégantic derailment and fire
Watch the animation

Other resources

TSB Laboratory Reports
Rail statistics

Investigation information

Map showing the location of the occurrence

Investigation team


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Class of investigation

This is a class 2 investigation. These investigations are complex and involve several safety issues requiring in-depth analysis. Class 2 investigations, which frequently result in recommendations, are generally completed within 600 days. For more information, see the Policy on Occurrence Classification.

TSB investigation process

There are 3 phases to a TSB investigation

  1. Field phase: a team of investigators examines the occurrence site and wreckage, interviews witnesses and collects pertinent information.
  2. Examination and analysis phase: the TSB reviews pertinent records, tests components of the wreckage in the lab, determines the sequence of events and identifies safety deficiencies. When safety deficiencies are suspected or confirmed, the TSB advises the appropriate authority without waiting until publication of the final report.
  3. Report phase: a confidential draft report is approved by the Board and sent to persons and corporations who are directly concerned by the report. They then have the opportunity to dispute or correct information they believe to be incorrect. The Board considers all representations before approving the final report, which is subsequently released to the public.

For more information, see our Investigation process page.

The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.