The British Bang April 18, 1947. Heligoland Island, Germany. The Royal Navy stacked 6,700 tons of explosives. The goal: destroy Nazi U-boat pens. The blast was felt across the North Sea. It was the largest non-nuclear explosion ever. The island survived. Just barely reshaped.
Source
https://en.wikipedia.org/wiki/Operation_Big_BangSpot an error? Email hello@thefact5.com with a source — we correct visibly.