The incident was not a question of whether the grizzly enclosure was up to speed in terms of zoo safety standards. Zoo officials said the enclosure meets or exceeds all of those national standards in place. Investigators say it appears the man who somehow climbed inside the exhibit came to the zoo Saturday intending to do exactly that.
Not only do zoo officials have no idea why the man decided to climb into an enclosure with two 500-pound female grizzly bears, they still do not know exactly how he did it.
"This takes a very concerted and direct effort on the individual's part," Bob Jenkins, the zoo's Vice President of Institutional Advancement said Sunday.
The barriers Kenneth Herron managed to get past include a 14-foot deep moat, a 15- to 20-foot tall wall, and hot wires that surround virtually the entire enclosure. All those things are designed to keep the animals in, but not necessarily to keep the humans out.
"Suffice it to say, anyone who enters a cage with a wild animal is someone who may have some type of mental problems," said Capt. John Loftus with the San Francisco police.
Police say Herron underwent a psychiatric evaluation.
"The individual, based on my own observations, was totally incommunicative with the police department, was, I would say, stoic in his response, almost zombie like," Jenkins said.
One couple watched in fear as zoo staff swarmed the enclosure and tried to distract one of the bears as it curiously hovered over Herron and took a few swats at his foot.
"There was gunshot that startled everyone in the crowd," recalled Bob Whiteman.
That warning shot fired by a zoo keeper from a 12-guage shotgun seemed to work. All the while, Herron lay there frozen.
"He didn't move the entire time. His feet did not move. The bear was standing right over him. Nothing," said Nica DeStefano.
Zoo officials say that is about the only thing he did right.
"If he had tried to hit the bear or shoo it away or something like that, it would have probably evoked a deadly response," Jenkins said.
There was a deadly response at the zoo in 2007 when a tiger escaped and attacked three people, killing one of them. But, this time around new emergency response plans implemented since then seemed to work.
Executive Director Tanya Peterson said, "Our number one message to the public is that the zoo remains safe. And, that remains our number one priority."
The zoo was back open for business as usual Sunday. The transient who was arrested is facing park code violations for trespassing. Authorities say he has a previous criminal history for making criminal threats and a weapons violation.