Look at all these incidents that have occurred there (listed in the Montreal Gazette article in the above link)...I don't track zoos, but this seems like an unusually high number of casualties.
The Calgary Zoo is again under scrutiny as details emerged Friday about how a capybara, a species of giant South American rodent, died after becoming caught in a hydraulic door last weekend as it was being moved from one area to another...
The fatality is one in a string of animal deaths in recent years. Incidents include a hippo who died in transport from Denver and a Turkmenian markhor, a species of wild goat, hung itself at the zoo after becoming trapped by a rope.
In April 2009, unseasonably cold weather froze two whopping crane eggs. They were a part of the zoo’s breeding program for the rare birds.
In November 2008, a virus killed a 15-month-old Asian elephant calf named Malti. She had been showing symptoms of the potentially lethal elephant herpesvirus, which leads to internal bleeding and heart failure.
In May 2008, 41 of the 43 rays at the Calgary Zoo’s 37,000-litre touch-tank died. The zoo blamed human error for the deaths, saying it didn’t have the expertise to manage the fish and that a lack of dissolved oxygen led to the deaths.
And an incident in June 2009, while it didn’t involve death, certainly drew controversy. Zoo patrons were shocked to see Barika, a western lowland gorilla, holding a knife and apparently pointing it at another primate in the enclosure. A zookeeper had left the knife behind in the exhibit. The Canadian Association of Zoos and Aquariums has since cleared the Calgary Zoo in the incident.