Snippet from Wikipedia: Wall Street bombing

The Wall Street bombing was an act of terrorism on Wall Street at 12:01 pm on Thursday, September 16, 1920. The blast killed 30 people immediately, and another 10 later died of wounds that they sustained in the blast. There were 143 seriously injured, and the total number of injured was in the hundreds.^: 160–61

The bombing was never solved, although investigators and historians believe it was carried out by Galleanists, a group responsible for a series of bombings the previous year.

Attack

At noon, a horse-drawn wagon passed by lunchtime crowds on Wall Street and stopped across the street from the headquarters of the J.P. Morgan & Co. bank at 23 Wall Street, on the Financial District's busiest corner. Inside the wagon, 100 pounds (45 kg) of dynamite with 500 pounds (230 kg) of heavy, cast-iron sash weights exploded in a timer-set detonation,^: 77 sending the weights tearing through the air. The horse and wagon were blasted into small fragments, but the driver was seen by witnesses leaving the vehicle and escaping down a side street.

The 40 fatalities were mostly young people who worked as messengers, stenographers, clerks, and brokers. Many of the wounded suffered severe injuries.^: 329–30 The bomb caused more than US$2 million ($31.4 million today) in property damage and destroyed most of the interior spaces of the Morgan building.

Within one minute of the explosion, William H. Remick, president of the New York Stock Exchange (NYSE), suspended trading in order to prevent a panic.

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