Video: 'Gas On The Western Front - Baptism of Fire for Canada I THE GREAT WAR Week 39' (Apr. 22, 1915 at 1:20)

(Thursday, April 22, 1915, around 5:00 p.m. Central European Time; part of the Western Front of World War I) — The first full-scale use of deadly chemicals in warfare took place today as German forces unleashed chlorine gas against Allied troops at the start of the Second Battle of Ypres in Belgium during World War I; thousands of soldiers are believed to have died.

Video: 'The Great War and the Shaping of the 20th Century - #3 Total War' (Apr. 22, 1915, at 33:35)