On Saturday, a dramatic moment unfolded at the San Diego Zoo when a gorilla charged toward a glass barrier, startling onlookers.

The gorilla, a 10-year-old named Denny, managed to shatter one of the three layers of tempered glass that separates the animals from their visitors, according to a report from KFOR on Monday.

Fortunately, no injuries were reported, and zoo officials confirmed that Denny remained unharmed during the incident. At the time, another gorilla was also in the enclosure, and both animals have since been moved to a private area for their care while repairs to the barrier are underway.

Video captured the intense moment when Denny charged at the glass wall, leaving those who witnessed it visibly shocked and gasping in surprise.

Katya Sutil, a zoo visitor, recounted that many people were preoccupied with their phones when the startling event occurred.

“He hit it with his elbow or forearm, like right in the glass directly in front of my face. When it hit in front me, I was so jolted I fell back a few feet. When I looked up to see what had happened, I saw the gorilla staring directly at me, making eye contact with me, and then a giant crack… 6 feet. It was pretty big,” she recalled.

An image shows the large crack in the glass:

The KFOR article said Denny is a western lowland gorilla. Per the World Wildlife Fund’s (WWF) website, those are the most numerous and widespread of the subspecies:

Populations can be found in Cameroon, the Central African Republic, Equatorial Guinea, Gabon, and the Republic of Congo, with possibly some remnant populations in the Democratic Republic of the Congo. The exact number of western lowland gorillas is not known because they inhabit some of the most dense and remote rain forests in Africa. However, significant populations still exist, including in the remote swampy forests of the Republic of Congo.

“Large numbers have not protected the western lowland gorilla from decline. Because of poaching and disease, the gorilla’s numbers have declined by more than 60% over the last 20 to 25 years,” the site noted.