Coffeyville, Kansas, USA-oil spill dead zone sign. Animal skulls and signs remain as a protest in the dead zone contaminated area after a oil spill at the Coffeyville Resources oil refinery in 2007. The refinery discharged more than 2000 barrels of oil and related products during a flood of the Verdigris River. Fifteen years after the spill, there are few homes remaining in the contaminated area.
