Wikipedia
Storofsen
Storofsen was a flood disaster which struck eastern Norway in July 1789. 63 persons perished, thousands of houses were totally damaged, and thousands of livestock drowned. The rivers Glomma and Gudbrandsdalslågen overflooded, and the water level of Mjøsa rose to ten meters above its normal level.
The Kvikne Copper Works were largely damaged by the flood, and this virtually ended the operation of the mines.