MADISON, WISCONSIN, US — Two senior Didion Milling employees on Feb. 15 were sentenced to two years in prison by a federal judge for falsifying record and obstructing an investigation of a fatal explosion at the company’s corn mill in Cambria, Wisconsin, US, in 2017, the Associated Press reported.

Derrick Clark, 50, Didion Milling’s vice president of operations, and Shawn Mesner, 45, the company’s former food safety superintendent, were sentenced to two-year prison terms by US District Judge James Peterson. Clark and Mesner were convicted on multiple safety environmental and fraud charges in October 2023. Clark was convicted of making false Clean Air Act compliance certifications and lying to investigators during a deposition. Mesner was found guilty of conspiring to mislead Occupational Safety and Health Administration (OSHA) investigators by lying on sanitation records that tracked cleanings.

The corn dust explosion on May 31, 2017, killed five people. Grain dust is explosive, and a high concentration in a confined space is dangerous. Federal regulations require grain mill operators to perform regular cleanings to reduce dust accumulations that could fuel a blast.

Didion Milling pleaded guilty in September to charges that its employees falsified environmental and safety compliance records for years leading up to the explosion. The company agreed to pay a $1 million fine and $10.25 million to the estates of the five workers who were killed.

Didion Milling Inc. also will pay $1.8 million in penalties and make extensive safety and health improvements as part of an agreement reached with the US Department of Labor (DOL). Didion Milling agreed to the penalties and a long list of safety improvements to settle an OSHA investigation of the explosion.

Didion Milling shift superintendents Nicholas Booker, Michael Bright and Joel Niemeyer previously pleaded guilty to false statement charges for participating in the falsification of the cleaning logs and baghouse logs. Didion Milling shift superintendent Anthony Hess pleaded guilty to obstructing OSHA by making false and misleading statements about the accuracy of the cleaning log. Former Didion Milling environmental manager Joseph Winch previously pleaded guilty to conspiracy to conceal environmental violations from regulators by falsifying compliance certifications and providing falsified logs.