U.S. soldiers training to remove gas from trenches

United States soldiers “getting the gas out of the trenches” at Camp Upton, New York, on March 9, 1918. "After the gas attack, this soldier protected by his mask and respirator goes into the trench and with a shovel-like contrivance beats the heavy gases out of the trenches. The poisonous gases are heavy and cling to the ground for a considerable period of time before they are sufficiently diluted with air to make the removal of gas masks safe. This is part of the training U.S. soldiers get in combating gas at Camp Upton." Camp Upton was a port of embarkation of the U.S. Army during World War I. It was located in Yaphank, New York in Suffolk County on Long Island, on the present-day location of Brookhaven National Laboratory. Photographer: Underwood & Underwood. National Archives and Records Administration, cataloged under the National Archives Identifier (NAID) 26424052. (This image is a work of a U.S. military or Department of Defense employee, taken or made as part of that person's official duties. As a work of the U.S. federal government, the image is in the public domain in the United States. Photograph edited by Dr. Douglas J Lanska.)