Every few years an M6 earthquake hits Italy. At the epicentre all the buildings fall down and kill everybody. Yet, for any given location, an earthquake only hits every 500 years. So, all those people are dancing in the streets like the little pig with the straw house.
I have decided there is a 'sweet spot' at the 1 in 500 per year probability, where you have the most deaths. At the 1 in 100 years, you have living memory and everybody builds better, like California. As well, all the old buildings from a 100 years ago have been already knocked down in the last earthquake.
Every single disastrous earthquake has been at these odds, yet nobody does anything. I'm just picking on Toronto for now, but it goes for every city. Basically, officials always think that if it is out of living memory, it can never happen. We'll call this event an M7, although it could be 6.5.
Toronto is like every Italian hilltop village. Why worry? Why do anything? The only way to get people concerned is to lie through your teeth, and say if Vancouver hasn't had an earthquake for 300 years, it's going to happen tomorrow. In reality, they are still at the same odds as everybody else. There is no master clock that ticks down.
Vancouver is lucky that the Japanese were around to record the earthquake. In India, because of the wars and such there are no ancient records of earthquakes. The Chinese have some old records.
If you look at the lake sediments, you can see that this type of big earthquake is a regular thing for Toronto, yet we have not had the benefit of Japanese record keeping. Ignorance is bliss.