The first use of gas in the first world war was the deployment of non-lethal tear gas by the French in 1914. The first use of lethal gas was by the Germans in 1915. The next major advancement of the first world war is the "Little Willie" tank by the British in 1915. Most of the fundamental changes in weapons used in the first world war were invented prior to the start of the war. The major changes in handheld weapons were increased fire rate, range and accuracy. These changes made for massive increases in casualties. The lethal effects of these weapons were compounded by the incompetence of the commanding officers. These weapons also changed the way the war was fought forcing the soldiers into trenches to avoid immediate death. The trenches also created an environment in which gas warfare could easily be used to wipe out thousands of unsuspecting troops. The militaries quickly devised ways to counteract these new technologies. This is evidenced by the use of gas masks in response to the use of gases.