On 21 September 2001 in Toulouse, an explosion destroyed the AZF fertiliser factory (for AZote Fertilisants, or Nitrogen Fertilisers) belonging to the Grande Paroisse company(Total Group).
The cause of this explosion, which led to 31 deaths and 4,500 injured (in addition to significant damage to the surrounding area) was a stock of 300 to 400 tonnes of ammonium nitrate (NH4NO3) intended for the production of fertiliser.
According to the investigation, accidental contact of this ammonium nitrate with 500 kg of chlorinated products, due to human error, seems to have caused the detonation that flattened the factory.
The AZF plant in Toulouse before the explosion. © Anton Merlina Bonnafous, Wikimedia CC by-sa 3.0