As Environment Canada meteorologist David Philips said Wednesday, those 81 deaths changed how civic planners now approach development along waterways in urban areas.
"It was realized that we had transformed the fabric of the city the wrong way," Phillips said on CBC Radio's Metro Morning. "In many ways the legacy of Hazel was to inspire a revolution in floodplain management."
Phillips, who will speak tonight at Lambton House about the flood and its legacy on the city, told host Matt Galloway that prior to the storm, many in Toronto thought hurricanes could never happen this far north.
Instead a storm came from the south after weeks of steady rain in the city. When it arrived, the already saturated ground could hold no more water.
"The rivers were engorged with water," said Phillips. "About 90 per cent of what fell in the skies got into the Humber River and other river systems. It was clearly a huge meteorological event."
In the city's west end, Hazel created what Phillips calls a "freshwater tsunami," swelling the Humber River by six metres in an hour, creating waves more than five metres high and a current moving at almost 50 kilometres an hour.
Cars were washed into rivers and some people clung to the roofs of their houses. The lucky ones were rescued by helicopter. Others were washed away, their bodies never recovered.
It was realized that this was a mistake," said Phillips. In addition to keeping development out of river basins, Phillips said the storm prompted engineers to incorporate flood planning into their designs.
Phillips's talk about Hurricane Hazel and its legacy happens Wednesday night at 7:30 p.m. at Lambton House. You can find more information here.