Rafe Kelley informed me that Toronto has one of the most active Parkour communities in North America and the world.
They have a great website: PKTO.ca
On safety:
Parkour demands as much or as little as you want to put into it, you never have to cross the boundaries of risk at all if you feel that is your path. In the 4 years we have been around, there has been very few injuries and we take great pride in knowing that we have been one of the safest Parkour scenes in the world. It is a common misconception as well that Parkour is ‘extreme’ and ‘roof top jumping’, but it couldn’t be further from the truth. 99.9% of our meets take place on ground level, using normal rails and objects.
Realistically speaking, the greatest risk at a normal training meet is getting dehydrated, and if you are VERY unlucky, a sprained ankle is about the worst you will probably ever get.
Canada’s largest Parkour community serving Toronto and Southern Ontario – FAQs
PKTO.ca – more photos
Gymnastics Coaching.com 