A dam break at a mine in northwestern Romania on Friday dumped 20,000 tons of lead, zinc, and other metals, contaminating three rivers, including the Tisza, which was severely polluted by a deadly cyanide spill from another Romanian mine accident six weeks ago. The pollution from the latest spill traveled downstream and hit Hungary on Saturday. Hungary plans to ask the European Union to identify potential environmental trouble spots in neighboring Romania, and Hungarian Premier Viktor Orban hinted that his nation might sue Romania. The Romanian environment minister counted 41 mining sites in Romania that pose a danger to the environment and said he will demand that mine operators tell him what they are doing to prevent accidents.