Ajka alumina plant accident

The Ajka alumina plant accident in October 2010 was a caustic waste reservoir chain collapse at the Ajkai Timföldgyár alumina plant in Ajka, Veszprém County, in western Hungary. On 4 October 2010, at 12:25 CEST (10:25 UTC), the northwestern corner of the dam of reservoir number 10 collapsed, releasing approximately one million cubic metres (35 million cubic feet) of liquid waste from red mud lakes.

Source: Wikipedia — Ajka alumina plant accident (CC BY-SA 4.0)