Oppau explosion

On these grounds, the material handled by the plant, nominally a 50/50 mixture, was considered stable enough to be stored in 50,000-tonne lots, more than ten times the amount involved in the disaster.

There is also evidence that the lot in question was not of uniform composition and contained pockets of up to several dozen metric tons of mixture enriched in ammonium nitrate.

[4] Two months earlier, at Kriewald, then part of Germany, 19 people had died when 30 metric tons of ammonium nitrate detonated under similar circumstances.

[4][6] The explosions were heard as two loud bangs in north-eastern France and in Munich, more than 300 km away, and are estimated to have contained an energy of 1–2 kilotonnes TNT equivalent.

In Heidelberg (30 km (19 mi) from Oppau), traffic was stopped by the mass of broken glass on the streets, a tram was derailed, and some roofs were destroyed.