20 were killed and the offices were destroyed in the attack.

The Times had run a number of anti-union editorials.

The owner of the Times, Harrison Otis, hired William J Burns, a private investigator.

Burns' inquiries led him to the Bridge and Structural Iron Workers Union, and their treasurer, John J McNamara. Burns apparently got a confession out of Ortie McManigal, who said he had acted as an intermediary between McNamara and a couple of bomb experts.

Burns managed to get John McNamara and his brother to California where the trial was to take place. The union raised a large defense fund, and hired Clarence Darrow, the legendary defense attorney.

Unfortunately for McNamara, Darrow's investigations showed that his clients were clearly guilty. A plea bargain was struck. The McNamara's pled guilty to avoid the death penalty.

Then it got messy. Clarence Darrow was prosecuted for bribery by Harrison Otis. The Union deserted Darrow and refused to help in his defense.

Darrow got a mistrial and then was acquitted at a second trial.