According to the cats over at the Chron, an "18-page 'Emergency Procedures' manual, written in 2006, spells out what zookeepers, guards and even the receptionist in the main office are supposed to do if a 'Siberian tiger is out of its enclosure' or any other dangerous animal escapes." (It's always the receptionist's fault, isn't it? The fall guys of the modern world, really.)
Basically, such emergency procedures as a "Code One" call, a shooting team, and a veterinary staff that is supposed to "' gather chemical immobilization equipment in preparation for anesthetizing the animal'" were not followed on Christmas Day's fatal tiger attack.
The Chron also goes on to report that some SF Zoo visitors claim that "that they were inside the zoo at the time, unaware that a tiger was loose until after the animal was dead." And that the most closely followed course of action was the one in which all "zoo custodians, handymen and popcorn vendors ... 'remain inside (and) close the door.'"