 Several more changes were made in 2011, the rule changes were announced after six animals died at the 2010 Stampede and were met with mixed reactions from both cowboys and animal welfare groups.Such changes have not completely eliminated all risks; periodic accidents have continued to result in the deaths of horses and livestock.One of the deadliest incidents in Stampede history occurred in 2005 when, late in a trail ride meant to help celebrate the province's centennial, a group of about 200 horses spooked and in the melee nine horses were killed after they were pushed off a city bridge into the Bow River.