A bug allowing Death Knight players in World of Warcraft to cast plagues on friendly targets sparked an epidemic last night.

A bug allowing Death Knight players in World of Warcraft to cast plagues on friendly targets sparked an epidemic last night, reports WoW Insider. The bug has since been patched.

Unlike the infamous Corrupted Blood plague in 2005, which caused mass deaths server-wide, the bug was not contagious to other characters. Infected Death Knights could only plague characters voluntarily, and as WoW Insider reports, "decided global extinction was the path to success when presented with the ability to enact it."

The Death Knight plague occurred only a day after Corrupted Blood's 7th anniversary on September 13th. A screenshot gallery of the plague's carnage is available at WoW Insider.