The spell was intended to last only seconds and function only within the new area of Zul'Gurub. However, a bug slipped through that allowed pets and minions to take the affliction out of its intended confines.
A pandemic that quickly killed lower-level characters and frustrated higher-leveled ones ensued. This changed normal game-play tremendously.
Players responded in different ways, but reactions resembled real-world behaviors.Some characters with healing abilities volunteered their services; some lower-level characters directed people away from infected areas; some characters would flee to uninfected areas, and some characters attempted to deliberately spread the disease to others in a terrorist fashion.
Urban areas were "filled to the brim with corpses" and the "city streets literally white with the bones of the dead."
The virtual plague was studied by epidemiologists for its implications of how human populations could react to a real-world epidemic. Anti-terrorism officials also studied the event—noting the implications of some players planning and perpetrating a virtual biological attack.
The Centers for Disease Control and Prevention contacted Blizzard Entertainment and asked for statistics on this event for research purposes, but were told that it was a glitch.
