Wall Street bombing, 1920.

At lunchtime on September 16, 1920, as banking clerks and businessmen bustled through the streets, a massive bomb tore through the Financial District. Set off from a rickety horse-drawn wagon at the corner of Wall and Broad Streets, the bomb was heard AND felt for blocks. It derailed a streetcar a block away, sent debris as high as the 34th floor of a neighboring building, and created a rain shower of glass from broken windows. In total 38 men and women were killed, while hundreds were injured.

Though the investigation into the culprits and motivations of the terrorism went unsolved, it was believed that the business of J.P Morgan was the intended target (who some felt had profited from the horrors of World War I). Most of the dead though were not high-level bankers but secretaries and clerks. Historians believe that the action was carried out by Galleanists (Italian anarchists), who had been responsible for similar, though smaller bombings in 1910.

This was the deadliest domestic terror attack until the 1995 Oklahoma City Bombing.