Malee, left, and Chai, center, died at the Oklahoma City in October 2015 and January 2016, respectively. [Photo by Sarah Phipps]

The Oklahoma City Zoo is the worst in North America, according to an animal rights group's list of the worst zoos of 2016.

California-based In Defense of Animals released its rankings Wednesday. The top five also include the Natural Bridge Zoo in Rockbridge County, Virginia; the Honolulu Zoo, the Edmonton Valley Zoo in Alberta, Canada, and the Oregon Zoo in Portland.

Oklahoma City makes the list because of two elephants that died in its care in 2015 and 2016.

Chai died in January 2016 from a blood infection. Malee, an elephant born at the Oklahoma City Zoo, died in October 2015 from the elephant herpes virus.