When the gas valves froze (from the rapidly expanding gas), many German soldiers tried to open them. This left the Germans exposed to the Gas as well. By the end of the battle the Allies and Germans had suffered massive casualties in the attack. The Canadians alone suffered over 6000 casualties. Gas masks were none existent at the time. But a Canadian Ceramic maker was able to recognize the color of the gas. He immediately told the soldiers to urinate on a towel and put it over their face. This isolated (separated) the gas components and stopped the gas from killing the Canadian soldiers.