Residential construction is one of the most dangerous industries in Alberta. Here is a picture I snapped the other days of some roofers working on a neighbour's house. Note they are on bare plywood with snow cover more than 5 meters up and no one has a safety harness (in fact, there was no safety equipment at all and their handling of the nail guns was crazily cavalier).
Sadly, this is pretty typical of the industry. I'd like to name names, but the guys had no sign on their work truck as to their company. They also worked in the dark (using head lamps!) while it was snowing--somedays working more than 13 hours.
-- Bob Barnetson