Published: Nov 25, 2011 8:24 PM EST

CHICAGO (AP) - The endangered baby gorilla born nine days ago at the Lincoln Park Zoo has died.
    
Zoo workers found the baby gorilla dead Friday morning. The baby was being carried around by her mother. Workers let the mother gorilla, 16-year-old Bana, keep the baby for several hours "in order to make peace with what happened."
    
The zoo says Bana is a first-time mother. The baby's father is Kwan, a 22-year-old silverback gorilla.
    
The baby was the first Western lowland gorilla born at the zoo since 2005. She had not been named.
    
In a statement, the zoo says the baby appeared to be fully developed and a cause of death isn't known yet. A necropsy is planned.

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