No, this wasn't the work of Vigo the Carpathian or a bunch of overzealous Slayer fans. In the city of Luoyang, illegal manufacturing workshops dumped chemical dye in the Jian River. The dye turned the river an unpleasant shade of hemoglobin crimson. It's not clear what the health ramifications of this unholy mess will be, at least there's the cold comfort that the Earth hasn't punctured an aorta.
Misha Collins on What Made Supernatural Successful
Previously: Canada's river of slime, Antarctica's blood falls.