A gorilla smashed a glass enclosure at the San Diego Zoo (6 photos + 1 video)
This weekend, visitors to the San Diego Zoo were alarmed. A ten-year-old western lowland gorilla unexpectedly attacked the glass barrier of his enclosure, breaking one of the three protective layers. 
On Saturday afternoon, Danny, a 400-pound gorilla, broke a section of tempered glass. The primate charged toward the barrier, frightening families with children.
"It was like an earthquake, we didn't even realize he hit the glass right away," witness Jackie Dubler told 10News.
"It was really scary. But the guards acted quickly. The zoo staff did a great job."
The video shows visitors gasping as the glass shattered from the impact.
Some ran away, while others came closer to see the damage for themselves.
"If he had hit the glass again, it would have been a completely different situation," Dubler added.
San Diego Zoo officials later confirmed the animal was unharmed.
A few weeks ago, 30-year-old Maki, Danny's brother, died of a heart attack.
The gorilla's behavior, while shocking to onlookers, was not out of the ordinary.
"Males, especially adolescents, often behave this way," the keeper noted. "Bursts of energy, attacks, dragging objects, running—it's all natural."
Dr. Erin Riley, a primate behavior expert and professor of anthropology at San Diego State University, told CBS 8, "Gorillas, especially males, often display their strength. It's their way of showing off. It's important to remember that they don't like being looked at in the eye, and visitors don't always understand that."
Riley suggested that Denny felt threatened at the time.
Animal behaviorist Annie Petersen commented, "It might not have been aggression, but simply intense excitement or a desire to explore."
Western lowland gorillas are the largest primates on the planet. They reach heights of up to 1.8 meters and can weigh over 225 kg. In the wild, this species is endangered due to deforestation and poaching throughout Central Africa.
