On August 16 1996 in the Brookfield Zoo, a 3 year old boy fell into a Gorilla enclosure and lost consciousness. Binti Jua a female Lowland Gorilla, guarded the young boy from the other Gorillas in the enclosure, she then cradled him in her arm (while her own 17 month old baby was on her back) and carried him 60 feet to an entrance where zoo-keepers could retrieve him.
This isn’t an isolated case, on August 31 1986 at Jersey Zoo a 5 year old boy fell into a Gorilla enclosure and lost consciousness, a large male Gorilla named Jambo stood guard over the boy not allowing any of the others to come near, when the boy woke up and started crying all of the Gorillas backed off and zoo-keepers (along with an ambulance) were able to retrieve him safely.