This article is definitely a little late in the game, but its an interesting read in relation to how zoos nationwide are affected by local tragedies.
Essentially, the attack in San Francisco has caused zoos to re-evaluate the safety of their own enclosures, and, in some instances, add additional safeguards to new and existing exhibits. John Ball Zoo opened the Lions of Lake Manyara exhibit this summer, after having carefully considered the events in San Francisco.
The zoo community is very close-knitted. Issues that affect one zoo, also have effects elsewhere. Keep this in mind when designing for multiple zoos. We can always learn from each other.