It's difficult to speculate. “If something happened“ is very general terminology. As to how much it would ripple across, it would be very unfortunate for the people in that area, and I don't want to minimize that at all.
What we've seen when you look at past housing price cycles is the amount of contagion depends on a couple of factors. One of them is just how big the price adjustment is in that particular area and how important that area is to the rest of the economy. If it's relatively small, then contagion is probably a low risk. If it's quite large, however, particularly in an area like the GTA and Brampton, I would say that the chances are higher that there would be contagion to other markets, because it would affect price expectations in other markets. It really would just depend.
Whether or not this would lead to a very large macro-economic cycle, a recession, would again depend on what else was going on in the environment. If the economy were still growing and benefiting from growth in the U.S., that would be one case. If, at the same time, there were some negative events from outside that amplified that price adjustment, then it could create some macro-economic problems.