U.S. District Court Judge James Peterson for the Western District of Wisconsin has sentenced Didion Milling Inc. officials – including a corporate vice president and former food safety, environmental, and operations managers – for their role in a fatal explosion at a mill operated by Didion.

“These defendants put Didion workers in grave danger and five people tragically lost their lives, devastating their families and their community,” said Attorney General Merrick Garland. “Companies of all sizes should take note: failure to comply with our country’s workplace safety and environmental laws can cost workers their lives and put individual corporate managers in federal prison.”

On May 31, 2017, a fire originated in milling equipment at Didion’s corn mill in Cambria, Wisconsin. The fire led to a series of combustible dust explosions in the facility, killing five workers and seriously injuring others. The explosions also damaged and caused the collapse of multiple mill buildings. An investigation into Didion’s worker and food safety and environmental practices uncovered criminal violations of law attributable to both the company and senior officials.

Investigations of the explosion at Didion’s Cambria mill uncovered long-standing inadequate safety measures and improper handling of grain dust that Didion and its employees concealed through falsified documents and other obstructive conduct.

In October 2023, the Justice Department secured guilty pleas from the company, Didion, and company officials, as well as convictions against two more Didion officials. Last month, Judge Peterson sentenced the company last month to pay $10.25 million in restitution to the victims of the May 2017 explosion and a $1 million fine, as well as to serve five years of probation with special conditions related to oversight of Didion’s operations.

Last week, Didion Vice President of Operations Derrick Clark, was sentenced to two years in prison, a year of supervised release, and a $5,000 fine. Clark was convicted in October 2023 of conspiring to falsify documents relating to dust cleaning practices in the mill and the operation of air pollution prevention equipment and making false compliance certifications as Didion’s “responsible official” under the Clean Air Act. He was also convicted for obstructing the Occupational Safety and Health Administration’s (OSHA) investigation of the explosion at the corn mill by making false and misleading statements during a sworn deposition.

Former Environmental Manager Joseph Winch was sentenced to two years in prison, two years of supervised release, and a $10,000 fine for conspiring to falsify Didion’s environmental compliance certifications. Winch pleaded guilty to the conspiracy charge before trial, but the court’s sentencing took into consideration Winch’s effort to obstruct the trial of his co-defendants by committing perjury during his trial testimony.

Former Food Safety Superintendent Shawn Mesner was sentenced to two years in prison and a year of supervised release after being convicted in October 2023 of conspiring to commit fraud and to falsify Didion’s sanitation log. Falsification of the log was part of a scheme to mislead Didion’s customers and auditors about the company’s sanitation practices. The log also related to Didion’s compliance with worker safety protections, including the required cleanup of combustible dust, like fine grain dust, to prevent fires and explosions in grain handling facilities. The log purported to be a record of those dust cleanings. Mesner also provided untruthful testimony to OSHA during a sworn statement after the explosion.

Judge Peterson also sentenced three former Didion shift superintendents – Anthony Hess, Joel Niemeyer and Michael Bright – who were convicted of crimes relating to falsification of Didion’s sanitation log. All three pleaded guilty to felonies before trial and accepted responsibility for their actions. Hess was sentenced to a year of probation and a $5000 fine; Niemeyer was sentenced to a year of probation and a $1000 fine; and Bright was sentenced to a year of probation.

Nicholas Booker, a fourth shift superintendent who pleaded guilty to felonies is scheduled to be sentenced in March.

“Workplace and environmental safety are of paramount importance,” said Assistant Attorney General Todd Kim of the Justice Department’s Environment and Natural Resources Division. “We will continue seeking to enforce regulations designed to prevent workplace disasters, and also to punish deceptive conduct that would undermine the administration of these important federal programs.”

Acting Secretary of Labor Julie Su commented: “The Didion Milling dust explosion was a tragic incident resulting from a notorious industrial hazard. Individuals considering falsifying records are on notice that making false statements and attempting to obstruct our investigation are serious crimes and will be punished as such. The court’s sentences hold the company and these individuals accountable and send a clear message that cover-ups related to workplace safety will not be tolerated.”