Animal advocates are asking questions — but the San Francisco Zoo isn't answering them — after the sad and horrible death of the Zoo's youngest gorilla Friday night.

According to a statement released by the Zoo on Saturday, Kabibe, the Zoo's nearly 16-month-old female western lowland gorilla, was crushed by a hydraulic door in the gorillas' night quarters as the animals were headed in for the evening.

In the statement, the Zoo says that Kabibe "unexpectedly darted" beneath the door as it was closing.

"This type of accident is extremely rare," the statement read. "The Zoo wishes to assure the public that all animal care protocol at the facility is specifically designed with animal safety as the top priority."

The Chron reports that "there have been at least two other fatal incidents involving animals and hydraulic doors at zoos in Washington, D.C., and in Canada."

Elliot Katz, a veterinarian and founder of In Defense of Animals, tells the Chron that one way to prevent these deaths is a push-button mechanism allowing Zoo staff to stop the door from closing, or to even reverse its motion, thus “stop(ing) the movement of the gate, so the animal isn’t crushed or killed."

However, the Zoo wasn't answering questions regarding any safety measures in place, as a spokesperson says that "the Zoo will refrain from interviews and media visits at this time."

For some, this death and subsequent silence from the Zoo might be an unpleasant reminder of other incidents in the Zoo's past, including the Christmas Day, 2007 escape of their female Siberian Tiger in which one man died, two others were injured, and the tiger was killed in a hail of SFPD gunfire. Longer ago, in 1988, the Zoo's elephant program received harsh national criticism over allegations of mistreatment.

"The Zoo is investigating how and why this accident happened," they write in a statement, "and will review Zoo policies, procedures, and training in the days ahead to see if any changes are warranted."

It goes without saying that Zoo staff are still reeling from Kabibe's death, with one telling SFist under the condition of anonymity that "it's impossibly surreal, a nightmare. No one can believe it."

Born on July 17, 2013 at the SF Zoo to parents Nneka and Oscar Jonesy, Kabibe was initially underweight and was rejected by her mother, requiring round-the-clock postnatal care for the first six months of her life. She was eventually introduced the the Zoo's entire gorilla family, and was adopted by Bawang, her grandmother, "and had been inseparable ever since," the Zoo writes.

"Some animal deaths are more difficult to process than others," Zoo Executive Director and President Tanya Peterson writes, "and this tragedy has struck us all in the deepest way imaginable."

Here's some video of Kabibe in happier times:

Related: S.F. Zoo's Baby Gorilla Runs This Town, You're Just Living In It