In one of the worst coal ash spills in U.S. history, up to 27 million gallons of contaminated water and 82,000 tons of coal ash spilled into North Carolina's Dan River after a pipe burst underneath a waste pond. That is enough toxic sludge to fill more than 70 Olympic swimming pools. The river has turned grey for miles, and environmentalists say they have found arsenic levels 35 times higher than the maximum set by federal regulators. Did state regulators intentionally block lawsuits against Duke Energy in order to shield the company where Republican Gov. Pat McCrory worked for 28 years?