The San Francisco Zoo is at fault for last December's gruesome tiger attack on a keeper, according to an investigation by California's Division of Occupational Safety and Health (Cal-OSHA), the San Francisco Chronicle reports.

"It was obvious that any of the cats could reach through or under the bars and that a potential hazard zone extended approximately 18 inches from the cage face," concluded the agency’s report.

According to the Chronicle, Lori Komejan, 46, was mauled by Tatiana, a 350-pound Siberian tiger, on the afternoon of Dec. 22 as dozens of horrified visitors watched. The incident occurred inside the Lion House after a routine public feeding of the big cats.

"The flesh was torn from her right arm," Dean Fryer, spokesman for Cal-OSHA, the state's workplace safety agency, told the Chronicle. "It was peeled off, similar to peeling off a glove."

The investigation said zoo officials were aware that hazardous conditions existed at the Lion House, closed since Komejan was injured. Cal-OSHA ordered changes — which already have been made — in the setup of the cages and wants to impose an $18,000 penalty, which the zoo can appeal.

"The hazard of the great cats being able to reach through and/or under the bars of the cages had been known to the employer for some time," the report said, citing a Lion House operations manual.

Investigators found that the zoo was also remiss because employees were not trained in procedures that would ensure safety and compliance, such as a buddy system, or the use of specialized equipment such as extension tools, noise devices or repellent sprays.