The red mud disaster of Kolontar and Devecser is considered to be one of the greatest ecological catastrophies of Hungary. The western dam of a toxic red sludge reservoir located at Ajka ruptured on October 4, 2010. Red sludge or mud is a byproduct of refining bauxite into alumina, which took place at an alumina plant run by the Hungarian Alumina Production and Trading Company. As a result of the breach, the red mud contained there flooded the surrounding territory. The red mud reached surface water. The valleys of Torna and Marcal were polluted. There was a high risk of the pollution of Hungarys largest river, the Danube. It caused significant damage to the ecological and social structures of the region. 10 people died and the homes of 150 people were destroyed. One year later there had been some clean up, and MAL Hungarian Aluminum has been fined $647 million (472 million euros) for environmental damages. However, levels of toxicity are still dangerous.