San Francisco Zoo in California has hired an expert to investigate the recent accidental death of a 16-month-old gorilla, crushed under a closing hydraulic door.

The gorilla, known as Kabibe, was killed as zoo keepers moved the primates to their night time enclosure. The young animal unexpectedly darted through a closing hydraulic door separating the two areas and was crushed to death.

Speaking to ABC7 news, Investigator Terry Maple, who has been brought in to look at the incident, said: “[the door] has a mechanism around on it that is there to be operated in an emergency. It can be stopped and in this case it was not stopped in time to save this little gorilla."

Maple, who is a professor at the Florida Atlantic University, said Kabibe was carried into the night enclosure by her grandmother and primary caregiver Bawang, before running back through the closing door.

In a statement, the zoo said that Kabibe was initially removed from the enclosure and brought to the hospital. Her body was later brought back to the gorilla enclosure so that the troop could see the body – something customary for primate deaths.

"Bawang was allowed to touch and examine her,” said the statement. “Animal staff report that the gorilla family is showing normal signs of grief and loss and each gorilla is dealing with the death in its own way, according to their individual personalities. Since Friday (7 November), the group's energy and demeanour has been evolving each day, with a gradual appetite improvement and increased exploratory behaviour."