Visitors at the San Diego Zoo were left terrified over the weekend after a gorilla suddenly charged at the glass wall of its habitat, cracking one of its protective layers and sending crowds running in panic.
The incident, which happened on Saturday afternoon, involved Denny, a 10-year-old western lowland gorilla weighing around 400 pounds.
Witnesses said the moment felt like an earthquake when the powerful animal slammed into the thick glass barrier at full speed.
The Moment That Sent Visitors Running
Several visitors caught the dramatic scene on camera.
In the clips, Denny can be seen sprinting across his enclosure at the Gorilla Forest habitat before crashing into the viewing window.
Families screamed and backed away in shock as the glass cracked upon impact.
“It literally felt like an earthquake before we realized it was him hitting the glass,” visitor Jackie Doubler told 10News.
“It was pretty scary, but the zoo staff reacted really fast — security guards were there within seconds.”
Although the damage looked alarming, zoo officials later confirmed that only one of the three layers of the tempered glass had broken.
The gorilla was not hurt and was quickly moved to a secure area while the enclosure was inspected and repaired.
A Possible Reaction to Stress and Grief
Denny’s sudden outburst came just weeks after the death of his older brother Maka, a 30-year-old gorilla who died unexpectedly in August after suffering a cardiac arrest.
Some animal experts believe the young gorilla’s behavior could be linked to stress or emotional distress following his brother’s passing.
According to zoo officials, the behavior — though shocking to watch — isn’t entirely unusual.
“It’s common for young male gorillas to show bursts of energy or charging behavior,” a spokesperson explained.
“These can include running, dragging objects, or slamming into surfaces.”
Experts Explain What Might Have Happened
Dr. Erin Riley, a primate behavior specialist from San Diego State University, said Denny’s charge was likely part of what’s known as a “charging display.”
“Male gorillas often perform charging displays as a way to show dominance or test their environment,” Riley told CBS8.
“What visitors don’t always realize is that gorillas dislike direct eye contact — it can feel threatening to them.”
She added that the large weekend crowd might have made Denny feel uncomfortable or overstimulated.
“If there were a lot of people staring, shouting, or tapping on the glass, that could easily make him react,” she said.
Another expert, Dr. Annie Petersen, agreed that the behavior might not have been purely aggressive.
“It could have been excitement or curiosity rather than anger,” she explained. “Gorillas are highly intelligent and emotional creatures.
Sometimes they’re just expressing energy or reacting to something unexpected.”
Visitors Urged to Respect Animal Boundaries
After the commotion, other guests at the zoo reminded the public about the importance of respecting animals in captivity.
“They’re incredibly strong,” said visitor Andrea Corry. “People shouldn’t tap the glass or try to provoke them.
Just watch and appreciate them — that’s what we’re there for.”
The San Diego Zoo confirmed that both Denny and his enclosure companion will remain behind the scenes until the enclosure is fully repaired and deemed safe.
About the Species
Western lowland gorillas, native to the rainforests of central Africa, are the largest primates on Earth — capable of reaching six feet tall and weighing up to 500 pounds.
Sadly, they’re critically endangered due to habitat loss and poaching.
Despite the scare, zoo officials emphasized that Denny is safe and healthy, and the team remains dedicated to giving the gorillas a secure, enriched environment.