Merah, the second-oldest Sumatran orangutan in North America and a longtime resident of the St. Louis Zoo, has died. Zoo staff announced on social media they made the difficult decision to humanely euthanize Merah, 57, last week, saying she was suffering from health issues and her quality of life was declining. "Merah was a curious, gentle and attentive mother and role model within her family group," zoo leaders said in a statement.