Mounted on a wood storage crib at the Naval Aircraft Factory, Philadelphia, Pennsylvania, on 19 October 1918. As the sign indicates, the Spanish Influenza was then extremely active in Philadelphia, with many victims in the Philadelphia Navy Yard and the Naval Aircraft Factory. Note the sign's emphasis on the epidemic's damage to the war effort. This image is cropped from Photo # NH 41731. U.S. Naval History and Heritage Command Photograph.