About 300,000 people in the US state of West Virginia have been warned not to drink tap water after a chemical leak into a river near the state capital. Schools and businesses were closed in nine counties.
A foaming agent used in the coal preparation process leaked from a tank at Freedom Industries.
The BBC reports the spill was found after the state environmental protection department received a report of a strange odour near the Elk river on Thursday.
Officials found a storage unit which had leaked into the river.