A Hungarian court has acquitted 15 employees of a company whose burst reservoir in 2010 flooded three towns with toxic red sludge, killing 10 people.

Hungarian state media reported Thursday that a court in the city of Veszprem said the spill, Hungary's worst environmental disaster, had been caused by the collapse a reservoir wall due to "loss of stability originating in the subsoil." The court said that could not have been foreseen by the executives or employees of MAL, the Hungarian Aluminum Production and Trade company.

The verdict cleared the accused of all criminal charges, including reckless public endangerment and violating waste management regulations, but the judge said it would not affect lawsuits filed against MAL.

The spilled sludge was a highly caustic waste product of aluminum production.