Russian crews are struggling to clean up a massive diesel fuel spill that threatens waters in the Arctic. In May, an underground tank at a power plant in the Siberian city of Norilsk began to leak, and some 21,000 tons of diesel fuel were released. The company that owned the tank initially tried to clean up the spill on its own, without alerting authorities. It devastated land and rivers nearby. Russian President Vladimir Putin declared a state of emergency in Norilsk.