Colo, the oldest gorilla in captivity, dies aged 60

The oldest known gorilla to be born in captivity, a female named Colo, has died in the US aged 60.
 
Colo passed away in her sleep overnight at the Columbus Zoo and Aquarium in Ohio, less than a month after celebrating her birthday.
  
She was born at the zoo in December 1956 and is believed to be the first gorilla ever born in captivity. 

Colo, a Western lowland gorilla, lived for more than 20 years longer than the average captive gorilla.
 
Despite recently having a malignant tumour removed, Zookeepers said she was recovering well. 
The cause of her death is yet to be determined.  

SOURCE: BBC NEWS