2017, Bretislav Friedrich, Dieter Hoffmann, Jürgen Renn, Florian Schmaltz, Martin Wolf

On April 22, 1915, the German military released 150 tons of chlorine gas at Ypres, Belgium. Carried by a long-awaited wind, the chlorine cloud passed within a few minutes through the British and French trenches, leaving behind at least 1,000 dead and 4,000 injured.