There is undoubtedly more to this story than meets the eye. Wolves are generally not aggressive to people unless there is some sort of extenuating circumstances. I suspect that a cause for this incident will be identified. Unfortunately for the wolves, it will mean less contact with the keepers, which is part of the socialization needed to keep these animals happy and healthy in captivity.
Although incidents with wolves are rare, zookeeper incidents with cats are the number one cause of human deaths here in the US. Zoos, especially the large ones, have be responsible for like 4 out of the last 5 big cat caused deaths here in the US. Circuses and magic shows are a distant second, and the so-called 'pet owners' have the best safety record overall. This is based on statistics originally collected by animal right groups here in the US. When carefully analyzed, they showed that they were lying about where the real safety problems are (and that the problem is a very small problem compared to all the other ways you can die). The animal rights folks have since pulled these statistics from their sites, and we now keep them up to date.
We do not go in with our cats, and have caging that is up to current safety standards. So, we have not had any incidents or escapes.
