Several people have died and at least 10 were wounded after a large chemical explosion at the Nippon Dynawave Packaging paper mill in Longview, Washington, officials said on Tuesday. Emergency teams continued search and rescue and firefighting operations at the site late into the evening, while investigators worked to establish the exact number of casualties and the cause of the rupture.

What happened
Cowlitz County emergency dispatchers received the first reports of an explosion at the mill, about 130 miles south of Seattle, in the late morning. A tank holding “white liquor,” a caustic solution used in pulping, ruptured and detonated, producing a powerful blast that damaged plant buildings and sent employees running from the site, authorities said.

According to Cowlitz Fire and Rescue Chief Scott Goldstein, “There are an unknown number of fatalities at this moment. We have confirmed that there are fatalities, but the exact number is undetermined.” Initial reports put the number of people taken to hospital at 10, including one firefighter; injuries ranged from minor to critical, officials said.

Injuries and response
Ten people were transported to nearby hospitals, with most listed as employees of the factory and one as a responding firefighter, Cowlitz County Public Health sources confirmed. Chief Goldstein said injuries included burns and inhalation-related trauma. Nippon Dynawave later acknowledged “multiple critical injuries” among its workforce.

Local emergency crews, county hazmat teams and state environmental officials were dispatched to the scene. Washington Governor Bob Ferguson said the State Department of Ecology had sent specialists to assist with containment and environmental monitoring. Firefighting operations were reported as ongoing but stabilised by evening, with authorities urging residents to avoid the area while response teams secured the site.

Tank details and chemical risks
Company and county officials said the damaged tank had an estimated capacity of about 80,000 gallons (roughly 300,000 litres) and was about 60% full at the time of rupture. White liquor is a strongly alkaline mixture—principally sodium hydroxide with sodium sulfide—used to break down wood chips into pulp. It is corrosive and can cause severe chemical burns and respiratory harm if inhaled as vapour or aerosol.

Officials stressed there was no immediate threat to the wider community, saying containment and monitoring were under way to check for air and water contamination. Still, the presence of such a large quantity of a caustic chemical prompted a multi-agency response and on-site hazmat precautions.

Facility background
The Longview mill, owned by Nippon Dynawave Packaging—a subsidiary of Japan’s Nippon Paper Group—produces tissues, printer paper, single-serve food containers, cartons and other packaging lines. The plant employs roughly 1,000 people, according to the Washington State Department of Ecology, and supplies customers across North America and Asia.

The site has a history of industrial incidents. Local media recalled a major fire in July 2023 when large wood piles burned for several days, and regulators have previously inspected the facility for safety and environmental compliance. Company statements after earlier incidents indicated ongoing efforts to improve safety systems; investigators will now examine whether maintenance, equipment failure, process issues or human error contributed to Tuesday’s rupture.

Wider context and simultaneous events
The Longview blast comes as California emergency teams were still dealing with a separate chemical scare in Orange County involving an overheated methyl methacrylate storage tank that prompted large-scale evacuations days earlier. Officials said there was no link between the two incidents beyond both involving industrial chemical storage.

What’s next
Investigators from local authorities, state regulators and federal agencies are expected to inspect the plant, review maintenance and safety logs, and interview employees as part of the probe. Officials did not immediately release a timeline for completing those inquiries. Families of employees were being notified and the company set up a family assistance centre, according to county spokespeople.

Sources familiar with the response said scene stabilisation and hazardous-materials mitigation would continue into the night, with environmental monitoring to follow. Authorities asked the public to rely on official updates and to avoid the Longview plant area while emergency operations continue. Further casualty figures and details on the cause of the tank rupture are expected as investigators comb the site.