Two days after the attack, on December 27, 2007, the zoo retracted its prior claim that the grotto's moat wall was 18 feet (5.5 m) tall, after officials measured it and found it was actually 12.5 feet (3.8 m) tall. The AZA recommendation for big cat enclosures is a moat wall of 16.5 feet (5.0 m). Tatiana's paws were also found to carry concrete chips, suggesting that she climbed out of the moat using her claws on the wall.[28]
The attack was the first visitor fatality due to an animal escape at a member zoo in the history of the Association of Zoos and Aquariums, according to the association.[29]
A 1996 zoo visitor reported an incident in which a tiger leapt and got a paw on top of the wall but slipped down. She said that a zoo employee dismissed the incident as a regular occurrence and that her letter to the zoo's director went unanswered.[28][30]
It was not immediately apparent how Tatiana had escaped, but police said that Tatiana may have "leaped" or "climbed" the walls of her enclosure.[31] Police undertook a criminal investigation to determine whether one of the victims "climbed over a waist-high fence and then dangled a leg or other body part over the edge of a moat that kept the big cat away from the public"[1] but did not immediately provide public substantiation for this hypothesis.[24]
On February 16, 2008, the zoo re-opened the exterior tiger exhibit which was extensively renovated to meet the extension of the concrete moat wall up to the minimum height of 16 feet 4 inches from the bottom of the moat, installation of glass fencing on the top of the wall to extend the height to 19 feet, and installation of electrified "hotwire."[32]
The zoo also installed portable loudspeakers which remind visitors to leave promptly at the 5 p.m. closing time and "Protect the Animals" signs which read:
:foh: 
