CAMBRIA, WIS. — Didion Milling Inc. pleaded guilty to two federal criminal charges and agreed to pay millions in restitution for a 2017 explosion at its Cambria mill that killed five workers and injured others, according to the US Department of Justice.

The company will pay a $1 million fine and $10.25 million in restitution to the estates of the deceased workers. It also agreed to serve five years of “organizational probation,” during which time the Occupational Safety and Health Administration (OSHA) can inspect the Cambria mill without a warrant or advance notice and without undue delay or any specified reason. The inspections can occur no more than twice a year.

Didion Milling and six of its managers and superintendents were charged May 2022 in a nine-count criminal indictment for its alleged role in failing to ensure work was done to safely handle combustible corn dust and keeping deliberately false records before the May 31, 2017, explosion.

The company pleaded guilty to charges of falsifying records related to its Occupational Safety and Health Act and Clean Air Act obligations to conceal violations from government agencies.

“Today’s guilty plea should send a message to all employers that we will not tolerate lying to OSHA, EPA and EPA’s state partners as they seek to fulfill their mandates to ensure the safety of workers and protect public health and the environment,” said Assistant Attorney General Todd Kim of the Justice Department’s Environment and Natural Resources Division. “Our thoughts continue to be with the victims of the May 2017 explosion. As demonstrated by today’s action, we will vigorously pursue restitution for victims of workplace incidents.”

According to court documents, Didion Milling was required to operate “baghouses,” equipment designed to prevent particulate matter, such as corn dust, from being released into the environment from the corn mill. From at least 2015 to May 2017, Didion Milling employees, including shift workers and shift superintendents, made false entries in the mill’s “baghouse logs,” disguising data meant to monitor and document whether the mill’s baghouse equipment was working properly to filter particulates from the air. Didion Milling’s environmental manager provided baghouse logs for 2015, 2016 and 2017 to environmental inspectors, knowing that they contained false entries, the DOJ said.

Didion Milling also was required under Occupational Safety and Health Act safety standards to develop and implement a housekeeping program to reduce the accumulation of fugitive grain dust within its corn mill. Didion Milling maintained a “master sanitation schedule” logbook listing each of the required dust cleanings and the specific dates by which the cleanings were supposed to be completed.

The sanitation logbook contained spaces for Didion Milling employees to record that the dust cleanings had been performed and that documentations procedures had been followed. On or about May 19, 2017, Didion Milling employees falsely initialed, signed and dated entries in the sanitation logbook for the week of May 1 through May 7, 2017, giving the appearance that the required dust cleanings were performed when they had not been.

Didion Milling provided the sanitation logbook containing the false May 2017 dust cleaning entries to OSHA during its investigation of the May 31, 2017, explosion at the Didion Milling corn mill.

A sentencing hearing before US District Court Judge James D. Peterson for the Western District of Wisconsin will be scheduled at a later date.

In a statement on Sept. 28, Riley Didion, chief executive officer, said the company was thankful to have reached the plea deal and was pleased most of the financial settlement will go to the workers’ estates.