BUDAPEST, Hu.—Hungarian officials have fined the metals company whose broken reservoir flooded several towns with toxic red sludge in October, killing 10 people, $472 million for environmental damages.

A 10-hectare (25-acre) reservoir at the MAL Rt. metals plant collapsed Oct. 4 2010 and released some 700,000 cubic meters of red sludge, a byproduct of aluminum production, on three towns in western Hungary. The highly caustic material also injured more than 150 people.

The Ministry of Rural Development says the fine levied by regional environmental authorities takes into account the unprecedented amount of hazardous material released during the incident.