Washington County paper mill deaths confirmed to be caused by hydrogen sulfide

The Maine medical examiner’s office has determined that two young men working at the Woodland Pulp paper mill died of complications of hydrogen sulfide exposure following a leak in late January. Kasie Malcolm, 20, was an engineering student from the University of Maine who interned at the mill. He [died hours after the Jan. 27 gas leak](https://www.pressherald.com/2026/01/28/umaine-student-dies-following-gas-leak-at-washington-county-mill/) in the facility’s bleach plant. Allen Hornberger, 26, had been working as a process engineer at the Washington County mill for five months. He spent three weeks in the hospital and [died Feb. 16](https://www.pressherald.com/2026/02/17/second-employee-dies-after-january-gas-leak-at-baileyville-plant/). Hydrogen sulfide had been suspected to be the gas that killed both men, but the chief medical examiner’s release of information is the first official confirmation. It’s unclear when the medical determination was made. The medical examiner’s office said it had not released the information prior to Thursday because of an investigation underway by Maine’s attorney general. The existence of the attorney general’s investigation has not previously been reported. When asked about it prior to Thursday, spokesperson Danna Hayes wrote, “The office cannot confirm the existence of, or comment on any investigation.” She also declined to comment on what the nature of a workplace death investigation could be. The chief medical examiner determined that the manner of death for both Malcolm and Hornberger was “accident,” which means they resulted from an unintentional injury. Separately, the Occupational Safety and Health Administration (OSHA) will determine whether the company violated safety laws and whether to issue any fines. OSHA has until late July to finish its evaluation. Another federal agency, the Chemical Safety Board, is also investigating the gas leak. Advertisement Woodland Pulp is the largest employer in Washington County. It makes hardwood pulp and manufactures toilet paper and paper towels on-site at St. Croix Tissue. It’s owned by the International Grand Investment Corp., whose directors are based in Hong Kong and Taiwan. [ Related [2 men died on the job, raising questions about safety in one of Maine’s most iconic industries](https://www.pressherald.com/2026/03/26/2-young-men-died-in-a-paper-mill-its-raising-questions-about-safety-in-one-of-maines-iconic-industries/) An ambulance was first dispatched to the paper mill at 3:28 p.m. on Jan. 27 to treat employees with headaches and other minor symptoms. Nearly three hours later, someone called 911 and said two people had been found in the bleach plant, a part of the facility where brown wood chips that have been turned into pulp get whitened and further broken down. Soon after, the Chemical Safety Board said in a written statement, “the incident may have involved the mixing of concentrated sulfuric acid with sulfurous compounds in an enclosed process sewer, resulting in the generation and release of hydrogen sulfide.” Malcolm was remembered at memorial services in March as a kind, generous person. Friends said that he hoped working in paper mills would launch him on a career in chemical engineering. Hornberger lived with his girlfriend and cat in Lee. His family has not spoken publicly about his death, but in a comment on his [obituary online](https://www.lombardofuneralhome.com/obituaries/allen-hornberger), Hornberger’s dad said, “You were my life. Everything I did was for you.” Copy the Story Link Tagged: [OSHA](https://www.pressherald.com/tag/osha/), [paper mill](https://www.pressherald.com/tag/paper-mill/) [](https://www.pressherald.com/author/rachel-estabrook) [Rachel EstabrookStaff Writer](https://www.pressherald.com/author/rachel-estabrook) Rachel Estabrook is an accountability reporter at the Portland Press Herald. Before joining the Press Herald in 2026, Rachel worked in the newsroom at Colorado Public Radio for 12 years. She's originally. [More by Rachel Estabrook](https://www.pressherald.com/author/rachel-estabrook)