Washington state chemical tank implosion death toll rises to 11; all missing workers recovered

May 30 (Reuters) — The death toll from a catastrophic chemical tank implosion at a paper processing plant in Longview, Washington, has climbed to 11, after rescue crews recovered the bodies of all nine workers who had been listed as missing since the Tuesday incident, officials said Saturday.

Authorities initially confirmed two fatalities shortly after the explosion tore through the Nippon Dynawave Packaging facility. The search for the remaining workers stretched over four days, with teams sifting through industrial debris indoors and deploying drones to scan the sprawling perimeter of the site, according to Kurt Stitch, deputy chief of Cowlitz 2 Fire & Rescue.

The tank, which contained roughly 900,000 gallons (3.4 million liters) of “white liquor” — a caustic mixture of sodium hydroxide and sodium sulfide used primarily in wood pulp processing — suffered a sudden implosion that investigators are still working to explain. White liquor is a staple chemical in the Kraft pulping process, commonly employed at paper mills across the Pacific Northwest.

Environmental monitoring teams confirmed that some of the spilled chemicals entered the nearby Columbia River, a major waterway that flows through Oregon and Washington to the Pacific Ocean. However, local officials stressed that air quality tests and samples from Longview’s municipal drinking water supply have so far detected no immediate negative health impacts.

The Longview plant has been owned since 2016 by Nippon Dynawave Packaging, a wholly owned subsidiary of Japan’s second-largest paper producer by revenue, Nippon Paper Industries. The Japanese conglomerate purchased the facility from Seattle-based timber giant Weyerhaeuser for $225 million, marking a significant expansion of its North American manufacturing footprint.

Industry analysts note that the incident could trigger heightened scrutiny of chemical storage safety at pulp and paper plants across the region, particularly at facilities handling large volumes of hazardous process chemicals. The U.S. Chemical Safety and Hazard Investigation Board has reportedly been contacted, though no official announcement on a formal probe has been made.

(Reporting by Anusha Shah in Bengaluru; Editing by William Mallard)