At 12 p.m. on September 16, 1920, a horse-drawn cart stopped in front of the headquarters of JP Morgan Bank at 23 Wall Street. Inside the cart were 100 pounds of dynamite and 500 pounds of iron weights. The driver of the cart quickly dismounted, leaving the bomb on the busiest corner New York’s Financial District as lunch-hour crowds filed past.
One minute later, a massive explosion shook Wall Street. Thirty people immediately died in the blast as the shockwave from the bomb sent the heavy iron weights ripping through the air. Another eight died within a few days, and an additional 143 were left seriously injured. At the time, it was the deadliest terror attack in U.S. history. Incredibly, the effects of the blast can be seen to this very day on 23 Wall Street.
Policemen and even financial workers on their lunch break rushed to the scene to provide aid. The police quickly commandeered any automobiles they could find to transport people to the hospital. And all trading on the stock exchange was suspended for the day. Having saved everyone they could, the authorities then tried to figure out what happened.
This wasn’t the first attempted bombing in the United States or even in New York. In 1910, a bomb planted by a labor agitator destroyed the offices of the Los Angeles Times. And in 1914, a trio of anarchists accidentally set off a bomb meant for John D. Rockefeller in their apartment in Harlem. But it was immediately clear to investigators that the Wall Street bombing was different.
Earlier bomb attacks always targeted property or the homes of important public figures. The bomb at 23 Wall Street seemed to have no target besides killing as many people as possible. It was an attack meant to spread fear and destruction. And it was one of the first incidents that we would recognize today as modern terrorism.
Investigators soon hit a wall. Attempts to track down the maker of the shoes the horse was wearing yielded no leads. Neither did an investigation of a famous tennis player who had sent postcards to friends warning them to avoid the area on September 16. It turns out that the man was mentally ill and had a habit of sending those types of warnings.
Part of the difficulty in solving the case was that there was no shortage of suspects. The anarchist and communist movements were in full swing at the time, and politically motivated bombings were very common. The year before the Wall Street bombing, followers of the Italian anarchist leader Luigi Galleani carried out a letter bomb campaign targeting prominent business and political leaders. And investigators soon settled on these “Galleanists” as the most likely suspects.
But in spite of an intensive investigation into known Galleanists, the authorities failed to find any hard evidence that they were behind the bombing. But they may have actually been closer to the truth than they knew. With the benefit of hindsight, many historians have concluded that the bomber was most likely a Galleanist named Mario Buda.
Buda was a committed anarchist who is believed to be have been responsible for several similar bombings across the country. And he was in New York on the day of the Wall Street bombing. However, he was never arrested or questioned by the police. Shortly after the bombing, he left for Italy and never returned to the U.S. In the following decades, several people who knew Buda even claimed that he admitted to being responsible for the bombing.
But to this day, the case remains officially unsolved.