At Chattanooga’s Walnut Street Bridge, a new memorial could ensure an old injustice is never forgotten. The bright blue bridge is usually a place for recreation, with men and women jogging, couples holding hands, and a scenic view beyond the handrails. Tourism officials tout the landmark as the world’s longest pedestrian bridge. It may be the Chattanooga's most iconic landmark, second only to the Choo Choo. It can also be a somber place. A crowd gathered for a ceremony where a bright green