Didion Officials Sentenced to Federal Prison for Fatal Explosion

Didion Milling Inc. officials — including a corporate vice president and former food safety, environmental, and operations managers — were sentenced by US District Court Judge James D. Peterson for the Western District of Wisconsin for their role in the 2017 fatal explosion at the Cambria, WI 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 B. 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.”

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 week, three defendants were sentenced to prison for their crimes, and another three were sentenced to probation. Sentencing for an additional defendant is scheduled for March.

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 OSHA investigation of the explosion 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. A fourth shift superintendent who pleaded guilty to felonies, Nicholas Booker, is scheduled to be sentenced in March.

The company as a whole pleaded guilty to falsifying its environmental and sanitation logs. 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. 

In 2022, the milling company was first charged for the explosion. Five workers died during the combustible dust explosion at the Cambria mill on May 31, 2017.

On that day, employees began to evacuate and attempted to notify other employees of the emergency using their radios, but conflicting radio traffic caused confusion with the message. A fire spread through the process equipment via interconnected dust collection systems resulting in explosions in some of the dust collection equipment. Secondary explosions subsequently occurred throughout the facility. Employees not within the immediate vicinity of the observed fire were unaware of the emergency and the need to evacuate prior to the explosions.

The US Chemical Safety and Hazard Investigation Board (CSB) released its final report into the deadly explosion in early December 2023. The investigation found that a key factor that contributed to the seriousness of the injuries was that Didion did not evaluate the risk of fires nor the need for flame-resistant personal protective equipment. Because of this, Didion did not provide personal protective equipment to employees in the mill, some of whom suffered burn injuries during the incident, including some fatal injuries.

Information on how to file a safety and health complaint about unsafe work conditions can be found here, as well as how to file a complaint of retaliation for having engaged in workplace safety-related protected activity.