The chemical tank that collapsed in late May, killing 11 people at a paper mill in Longview, Washington, was being worked on and scheduled for replacement at the time of the incident, according to statements from staff at the facility released by the Cowlitz County Sheriff’s Office.

Multiple employees of Nippon Dynawave Packaging Company questioned by sheriff’s deputies in the aftermath of the company’s tank rupture said they noticed scaffolding around the tank, indicating some work was being done on it. According to the documents, a maintenance supervisor at Nippon Dynawave told a deputy the tank “was scheduled to be replaced sometime next year.”

The exact reasons why the 900,000-gallon chemical tank was being serviced and slated for replacement are unknown. One employee said the scaffolding was related to insulation being put into the tank.

Several employees questioned by sheriff’s deputies said they had not been aware of any safety issues with the tank prior to its collapse. Others said the tank was “not in good working condition” and that they’d heard the tank had recently failed an inspection.

One employee told the sheriff’s department the tank was designed to hold a less corrosive chemical than the white liquor that burst out of it on the morning of May 26.

“Obviously, when you have a disaster like this and the loss of life like this, something went wrong,” Washington state Attorney General Nick Brown told OPB in a July interview. Brown’s office took over an investigation from the Cowlitz County prosecuting attorney’s office.

“When you have such a scale of mistakes or errors or whatever led to this tragedy, it obviously belies that a review needs to be done,” he said.

State and federal agencies are still investigating the cause of the tank failure. The investigatory documents describing the early hours of the incident were released to OPB from the sheriff’s office as part of a public records request. They were first reported by the Seattle Times.

Nippon Dynawave spokesperson Sam Jefferies declined to comment when asked about the statements from paper mill employees about the tank’s condition and scheduled replacement. He said in a written statement the company is supporting the independent state and federal investigations that are currently happening.

“At this time, we will not speculate about the root cause without the full facts. Doing so would be a disservice to our committed employees and to the families still mourning the loss of their loved ones,” he said in the statement.

A “loud rumble”

Shortly after 7:00 a.m., on the morning of May 26, employees of the paper mill gathered in a breakroom during a regular morning briefing. Mark Massey, a supervisor at the mill, told deputies he heard a “loud rumble” before the highly corrosive white liquor, used to break down woodchips, poured into the room.

“As others and himself were trying to escape he heard lots of yelling and screaming behind him,” Cowlitz County Sheriff’s Deputy Jesse White wrote in a report.

Nicholas Dykstra, a member of the mill’s mechanical crew, described being inside the breakroom as the accident unfolded to Detective Jason Hammer.

“Dykstra heard scaffolding outside start to break and fall, and he knew there was a problem with the holding tank,” Hammer wrote.

“Trust has been violated”

Agencies ranging from Washington State Labor and Industries to the state Attorney General’s office are now investigating the cause of the paper mill disaster, which Washington Gov. Bob Ferguson has called the “deadliest industrial tragedy in modern Washington state history.”

An initial assessment describing the known facts of the incident is expected from the U.S. Chemical Safety and Hazard Investigation Board.

Families of victims and workers impacted by the incident have retained attorneys. Vanessa Waldref, who formerly served as U.S. Attorney for the Eastern District of Washington, is representing three workers who were impacted by the accident.

“These employees, these workers, the community, trusted Nippon Dynawave to keep this workplace safe for everyone in the community,” Waldref said. “That trust has been violated.”

Both Waldref and Brown said investigations into incidents with this level of complexity move slowly.

In the meantime, some of the mill’s employees have begun to return to work. Others are still on paid leave as those investigations run their course. The company agreed to continue paying furloughed employees through Oct. 11.

News Source : https://www.opb.org/article/2026/08/24/longview-paper-mill-records-replacement-before-rupture/