We look at the largely forgotten 1937 Memorial Day Massacre, when police in Chicago shot at and gassed a peaceful gathering of striking steelworkers and their supporters, killing 10 people, most of them shot in the back. It was a time like today, when unions were growing stronger. The workers were on strike against Republic Steel, and the police attacked them with weapons supplied by the company. The tragic story is told in a new PBS documentary. “The mass media, right up to The New York Times, was supporting the police story that they had no choice but to open fire on this mob,” says Greg Mitchell, who directed the new PBS documentary, Memorial Day Massacre: Workers Die, Film Buried, and edited a companion book that is the first oral history on the tragedy. The film was produced by Lyn Goldfarb.