Investigators are looking into what killed two animals at the Animal Ark wildlife sanctuary near Reno. A 21 year old tiger died on February 6th. The very next day a 3 year old wolf died and a 9 year old cheetah was found comatose. The cheetah has recovered. Officials say they suspect that a barbiturate from an undetermined source caused the deaths, because the cheetah tested positive for the drug.