<p><br /> Emergency workers in Hungary have poured 1,000 tons of plaster into the Marcal River in an attempt to keep the toxic sludge spill from flowing into the River Danube.<br /> </p><p><br /> Officials were concerned about the sludge contaminating the1,775-mile-long river that passes through some of the continent's most pristine vistas from its origin in Germany to its end point emptying into the Black Sea.<br /> </p><p><br /> Emergency workers and construction crews have swept through the Hungarian towns hardest hit by a flood of toxic sludge, trying to clear roads and homes of acres of deep red mud and caustic water. The spill is currently 45 miles away from the Danube.<br /> </p><p><br /> A major evacuation took place after the disaster on Monday, when a gigantic sludge reservoir burst its banks at a metals plant in Ajka, a town 100 miles southwest of Budapest, the capital.<br /> </p><p><br /> Hungarian officials have declared a state of emergency, calling the spill "an ecological disaster" that could threaten the Danube River, one of Europe's great waterways.<br /> </p><p><br /> One of the continent's greatest treasures of wildlife, it has been the focus of a multi -billion dollar post-communist cleanup.<br /> </p><p><br /> However, high-risk industries such as Hungary's Ajkai Timfoldgyar alumina plant are still producing waste near some of its tributaries, posing a threat to the waterway.<br /> </p><p><br /> Environmental Affairs State Secretary Zoltan Illes called the spill an "ecological catastrophe," and Hungarian Prime Minister Viktor Orban acknowledged that authorities have been caught off guard by the disaster.<br /> </p><p><br /> Orban said the alumina plant and reservoir had been inspected only two weeks earlier and no irregularities had been found.<br /> </p><p><br /> At least four people have been killed by the sludge, three were still missing and 120 injured, many with burns.<br /> </p>
