More than a week after an explosion destroyed an oil rig in the Gulf of Mexico, thousands of gallons of oil continue to flow into the Gulf. The blast killed eleven workers, and created one of the largest oil spills in U.S. waters. As investigators search for the cause of the explosion, crews work around the clock to stop the flow of oil and contain the slick. Some of the oil may be set on fire to prevent a larger catastrophe and damage to the U.S. coastline.

David Biello, associate editor of energy and environment at Scientific American, explains the origins of the of the oil leak, why it’s so difficult to stop, and the tools used to clean it up.