The Disastrous Grand Valley – Tottenham Tornado (DONE)

Brutal F4 Tornado leaves 115km scar across southern Ontario

At about 4:15pm, the third tornado of the day touched down just NW of Arthur. This tornado would go on to last for over an hour and trek more than 100km across the heart of Southern Ontario. It would become the longest lasting tornado in Canadian history and leave behind a massive trail of death and destruction.

The tornado impacted several rural communities along its ruinous path from Arthur to Mouth Albert, but most notably struck was the town of Grand Valley, which took a direct hit. In it’s wake, part of the town resembled a bombed-out war zone with most of the buildings destroyed and once beautiful shade trees shredded. Unfortunately, there were also human losses as a man was killed in his pickup truck and a woman died when she was blown out of her house. Many others were injured to varying degrees. Some, including children barely escaped death as structures collapsed around them, luckily getting out with only minor injuries.

East of Grand Valley and a little less than half way through its lifespan, the tornado passed 4km north of downtown Orangeville. Here, as it crossed Highway 10 would it blast through an isolated strip mall known as the Mono Shopping Plaza. Half of the large 2 acre structure was reduced to a pile rubble with debris strewn hundred of meters downwind. Miraculously no one was killed in the mall but there were several injuries, with one of them being serious.

The tornado also struck dozens of rural residences and farms along it’s destructive path with the majority having to rebuild.¬†One such community was the area south of Tottenham where sadly two other people were killed. Houses and outbuildings in this community were decimated with some being wiped clean off their foundations. In total, 25 families lost their homes in the Tottenham area alone.

After being on the ground for nearly an hour, the tornado crossed over Highway 400 on the north side of the Holland Marsh. Along the north canal, hundreds of large willow trees were mangled and strewn about by the ferocious winds. Agricultural properties in and along the marsh sustained heavy damage as well. Some of the destruction was severe enough for locals to rename one of the marsh roads to “Tornado Drive”.

It was only after crossing the marsh that the tornado began to show signs of weakening. In the communities of Ansnorveldt and East Gwillimbury, there was only moderate to minor damage reported. In Mount Albert, damage was sporadic and mostly confined to uprooted trees and other light structures being affected. However, it took another 9km before the tornado was to lift off for good.


When it was all over, the impact of this monstrous tornado was staggering. After detailed ground and aerial surveys of the enormous area, officials concluded that the tornado had travelled a distance of 115km. This was and still stands as a Canadian record. In total, over 100 buildings were found to be destroyed, 200 damaged. A minimum of 69 injuries were reported, and sadly 4 deaths occurred.