AZF: French Factory Explosion

21 September 2001, 10h17. In the AZF factory, in Toulouse, France, a storage of around 300 tons ammonium nitrate exploded, injuring thousands and killing 31 people. 20 years later, never seen before footage and unpublished interviews show the minute by minute of this industrial disaster, the biggest in French history since WWII. (National Geographic)