Has anyone heard of this event? I just did. Before the United States' entry in to WWI, there was strong resistence among various organizations to becoming involved in the European theater. Business leaders apparently orchestrated a "Preparedness Day" march on Market Street in San Francisco to engender attitudes that everyone should be ready to join in with fighting the war. On July 22, 1916, in San Francisco's largest parade ever, a bomb went off near the Ferry building that killed 10 people, and injured 41. In typical form, a union leader was made the sacrifical lamb. Tom Mooney was prosecuted with perjured testimony --sentenced to death, but had his sentence commuted to life imprisonment, by President Woodrow Wilson --Mooney was released 20 years later. However, he died shortly thereafter. The person who did the deed has never been ascertained.