The earthquake also caused a landslide on Mount Tangjia which dammed the Jian River and created the Tangjiashan Quake Lake. The lake was once in danger of causing the Tangjiashan Dam to collapse and catastrophically flood downstream communities, totalling over a million persons. On June 10, 2008, the lake spilled through an artificially constructed sluice channel and flooded the evacuated town. No casualties were caused.