Emergency workers and construction crews in Hungary are trying to clean up a flood of toxic sludge, clearing roads and homes of acres of deep red mud and caustic water.

One million cubic meters of the toxic waste engulfed several towns on Monday after a massive sludge reservoir burst its banks at an alumina plant in Ajka, a town 100 miles southwest of Budapest, the capital. At least four people have been killed. Three were still missing and 120 injured, many with burns.

The material is a waste product in aluminum production that contains heavy metals and is toxic if ingested.

Erzsebet Veingartner was in her kitchen in the town of Kolontar, the town nearest the plant, when the 12-foot high wave of red sludge hit, sweeping away everything in its path.

"I looked outside and all I saw was the stream swelling like a huge wave," the 61-year-old widow told the Associated Press on Tuesday as she surveyed her backyard, still under 6 feet of noxious muck.

"I lost all my chickens, my ducks, my Rottweiler, and my potato patch. My late husband's tools and machinery were in the shed and it's all gone," sobbed the woman, who gets by on a $350 monthly pension. "I have a winter's worth of firewood in the basement and it's all useless now."

Hungarian officials have declared a state of emergency, calling the spill "an ecological disaster." There are also concerns that it could reach the Danube River and poison other areas of the European continent.