SAN FRANCISCO—The San Francisco Zoo has come under fire after the revelation of last week’s accident that resulted in the killing of a 16-month old gorilla, was caused by an electric door that has been deemed outdated and unsafe.

The chief investigator of the gorilla’s death determined that the electric door in question needed to be replaced.

Kabibe, an endangered Woodland Hills gorilla, was crushed by the door during the daily movement of animals from their daytime enclosures to their after-hours quarters.

Dr. Terry Maple, the gorilla expert hired by the zoo to investigate the accident, pointed out that an operator of the control panel, and by consequence, the emergency button, would not have a perfect view of all of the zoo’s doors as they close. Unlike a home garage door, these doors had not been designed to stop after contacting something.

Maple recommended that the zoo renovate its 30-year-old gorilla enclosure, installing a new system that would allow portable closing of the enclosure doors, affording operators a direct view of the enclosure as the doors close.

Kabibe’s death, also under investigation by the U.S. Department of Agriculture, is one in a series of enclosure-related injuries to gorillas, including the maiming of a gorilla named Monifa under an electric door in 2012.

Considering the 2007 Christmas Day escape and fatal mauling of a teenager by a Siberian tiger, as officials continue investigating, it could lead to a suspension or even a revoking of the zoo’s license.

Kabibe, a 16 month-old gorilla was a popular zoo attraction.