Police are investigating the slaughter of 100 husky dogs used during the 2010 Winter Olympics to pull tourist sleds in the Canadian ski resort of Whistler, authorities said Monday. The grisly killings were reportedly carried out by one worker over two days in April 2010 with a shotgun and a knife, with reports of injured dogs crawling out of a mass grave. Local media said the dogs were killed because business slumped in the two months following the Games and they were no longer needed by tourism companies Outdoor Adventures and Howling Dogs, which sell dog-sled rides to tourists.