The History of the Mississauga Train Derailment Remembered - Part 1

This week’s submission, along with the next several weeks, will focus on the story of the “Mississauga Miracle” – the 1979 train derailment and evacuation.

Modern Mississauga and Heritage Mississauga have come together to present an ongoing series called “Way Back Wednesday.” We’ll share information about the history of Mississauga here and answer your questions.

Today’s topic is the Mississauga Train Derailment Remembered - Part 1

On the evening of November 10, 1979, citizens in the young City of Mississauga were unaware that something catastrophic was about to occur.

Freight trains frequently carry hazardous materials through the City of Mississauga. CP train #54 was carrying 106 rail cars from Sarnia to Toronto on a weekly scheduled run. Thirty-eight cars were carrying cargo that the Canadian Transport Commission designated as hazardous materials, including liquid styrene, caustic soda, liquid petroleum products, including highly explosive propane and butane, and liquid chlorine.

At approximately 11:53 pm, as the train crossed Burnhamthorpe Road, an axle bearing failed and one rail car lost a pair of wheels. The train continued until, at approximately 11:56 pm at the Mavis Road crossing, 24 rail cars derailed. Massive explosions, caused by ruptures in butane- and propane-carrying rail cars, were seen more than 100 kilometres away. One explosion hurled a 90-ton tanker car filled with liquid propane more than 675 metres away from the derailment site. The night sky shone orange in the fire, and Mississauga residents could see, hear and feel the evolving emergency.

The initial cause of the derailment was a “hot box” – or an overheated journal box that connected the moving axle of the wheel to the car above. Car 33 had an older model journal box that had failed. When the dangling undercarriage of the damaged car left the rail tracks, 23 other cars followed it, 19 of which carried dangerous commodities.

2019 marks the 40th anniversary of the “Mississauga Miracle”. There are a number of ways to connect with the story of the derailment, including visiting exhibits at The Anchorage (Bradley Museum, 1620 Orr Road) and The Grange (Heritage Mississauga, 1921 Dundas Street West). You can also view the 1 hour documentary on YouTube commemorating a city’s memories on the 40th Anniversary: https://www.youtube.com/watch?v=-tLCu1oUvws