Two fatalities had been confirmed after the tank containing “white liquor” - a chemical solution of sodium hydroxide and sodium sulfide used in making paper pulp - imploded at a Nippon Dynawave Packaging facility on May 26, Reuters reported.
The search for the missing carried on through the week as recovery crews worked through debris in indoor areas and flew drones over the perimeter of the site, said Cowlitz 2 Fire & Rescue’s deputy chief, Kurt Stitch.
The ruptured tank contained about 3.4 million liters of white liquor, and tests confirmed that contamination entered the nearby Columbia River, officials have said, although no “negative health impacts” had been detected on air quality or the city of Longview’s drinking water.
Nippon Paper Industries, Japan’s second-biggest paper manufacturer by sales, acquired the Longview plant from Seattle-based timber company Weyerhaeuser for US$225 million and established the wholly owned subsidiary Nippon Dynawave Packaging in 2016.