Here's an online article which was originally published in Time magazine on December 27, 1937. The article was written on the federal conviction of 36 members of the Progressive Miners "of conspiring to blow up trains and thus interfere with 1) the mails and 2) interstate commerce."
While the verdicts dealt a near-fatal blow to the union, trial testimony also pointed to collusion between the coal operators and the United Mine Workers. That testimony was never refuted in the trial. Here's an excerpt from the Illinois State Journal's trial coverage, December 11, 1937.
“W.R. Swafford, Harrisburg, ...testified Friday he was instructed by an official of the Peabody Coal Co. to simulate a gun battle during miners’ riot in Harrisburg in October of 1933 to raise sympathy and get the militia out.
Swafford, ... said he acted under orders of W. C. Craggs,... at that time superintendent of the company’s No. 43 mine near Harrisburg.
... According to previous testimony presented in the trial, ...a mass meeting of miners was held in Harrisburg, a march was made on the mine, a gun battle followed, and troops were called out to restore order.
Swafford, ... said Craggs gave him a sawed-off shot gun and a rifle and four boxes of shells and told him to go out on the mine property to guard the mine’s fan house. ‘If anyone starts shooting,’ Swafford quoted Craggs as instructing him, ‘do all the shooting you can so we can raise sympathy and get the militia in here.’
...He also testified he saw a company-owned truck, covered with sheet iron leave the property about 10 p.m., and asserted he saw three machine guns, rifles, shotguns, ammunition, and a couple of boxes of dynamite in a mine office...
He asserted that earlier in 1933, from June 30 to July 5, he said about two hundred others were requested to stay in the mine to arouse sympathy and get the militia called out. Pressed by Prosecutor Welly K. Hopkins to tell who gave him those orders, the witness replied it was general talk at the time. ‘Didn’t you really stay in the mine because it was heavily picketed?’ Hopkins asked. ‘No,’ he replied, ‘I went home one night and was not molested. The company wanted us to look like we were picketed in.’”