One or several individuals used an exploit in World of Warcraft to turn several cities and locations in the game into death traps as NPC's and players alike fell victim to swift deaths on Sunday. Blizzard responded almost immediately with a hotfix to solve the issue and ensure it won't happen again, but they're still looking for the person or persons responsible.
"Earlier today, certain realms were affected by an in-game exploit, resulting in the deaths of player characters and non-player characters in some of the major cities. This exploit has already been hotfixed, so it should not be repeatable. It's safe to continue playing and adventuring in major cities and elsewhere in Azeroth.
As with any exploit, we are taking this disruptive action very seriously and conducting a thorough investigation. If you have information relating to this incident, please email [email protected]. We apologize for the inconvenience some of you experienced as a result of this and appreciate your understanding."