A 3-month-old gorilla has been seriously injured at Chicago's Lincoln Park Zoo while in an enclosure with other gorillas.
Zoo President Kevin Bell says they're not sure what caused the injury, although it appears to have been inflicted by another gorilla. Bell says there were no previous signs of violence from the group.
The baby gorilla named Nayembi suffered cuts to her face last week. Zoo workers quickly separated the mother and baby from the rest of the group.
Zoo officials are cautiously optimistic about a recovery.
The zoo has its own hospital where the gorilla is being treated.
A statement on the Lincoln Park Zoo's website says that in an encouraging sign the gorilla is playing during the day and getting plenty of sleep at night.