45 YEARS AGO: Huge explosion follows train derailment in Mississauga

It didn’t take Mississauga very long to grab international headlines within the first few years of its formal existence as a city.

Incorporated as a city in 1974, Mississauga made history on a grander scale five years later when, on Nov. 10, 1979, a huge explosion minutes before midnight roused tens of thousands of residents from their sleep.

A late Saturday night was just turning into Sunday morning when the dark Mississauga sky lit up like never before. And never again since.

The enormous explosion at the Mavis Road rail crossing just north of Dundas Street West sent the orange fireball that quickly followed about 1,000 feet into the midnight sky.

It was 11:56 p.m. and the growing city of Mississauga, with a new mayor named Hazel McCallion, was about to be forever changed.

Three minutes earlier, as a 106-car Toronto-bound train carrying 90 tonnes of chlorine and tankers full of other highly flammable materials including propane and butane sped by the Burnhamthorpe Road crossing, a red-hot set of train wheels fell off and flew 50 feet through the air.

The wheels landed in the backyard of a nearby home and, moments later, train cars began crashing into one another, 25 of them leaving the tracks.

Second explosion more powerful than the first

The explosion was sudden, and deafening. It rocked numerous neighbourhoods in the immediate vicinity and awakened tens of thousands of Mississauga residents who had gone to bed. Scores of others, meanwhile, were already at their windows, on their balconies and at the bottom of their driveways bearing witness to the massive fireball and trying to figure out what had blown up.

At 11:57 p.m., every available piece of firefighting equipment in Mississauga, including dozens of fire trucks, were sent to the scene of the explosion and crippled train.

As people across the city were still attempting to determine exactly what had happened and what was ablaze, and just how serious the situation was, a second explosion — considerably more powerful than the first — rocked the city at 12:01 a.m. as Saturday gave way to Sunday.

The flash of light was seen by people as far away as Niagara Falls, Oshawa and Peterborough.

Largest peacetime evacuation in North American history

“The noise awakens tens of thousands throughout Toronto. The blast was so powerful that one tanker is hurled a kilometre away,” Heritage Mississauga writes in its account of the historic event. “Firefighters do their best, but can make no impression on the raging flames. Eleven of the derailed tankers contain highly explosive propane, and one tanker held the 90 tons of chlorine.”

In stages over the next several hours and day, the vast majority of Mississauga residents were evacuated from their homes. Many would not return for nearly a week.

In all, more than 200,000 of the city’s 294,000 residents at the time were forced to leave their homes in what was then the largest peacetime evacuation in North American history.

Heritage Mississauga offers a full and detailed account of the entire ordeal, from the time the train left its starting point in Ohio earlier on Nov. 10, 1979 to nearly a week later when all residents finally returned to their homes to resume their lives.

The Mississauga train derailment changed the city — and other municipalities — in several ways, including making it a priority for the city to have a detailed, up-to-date emergency plan in place should disasters strike.