4072726 Wearing masks a Seattle street car during the Spanish flu epidemic (b/w photograph) by American Photographer, (20th century); Private Collection; (add.info.: The influenza pandemic 1918-20 known as Spanish flu killed 10-20% of those infected, current estimates say 50??00 million people worldwide During the epidemic, everyone on street cars had to wear a mask - 260,000 were made in 3 days by 120 workers of the Seattle Chapter of the American Red Cross); American, out of copyright.