Authorities in Longview, Washington, say two workers are confirmed dead and nine others are presumed dead following the implosion and rupture of a 900,000-gallon chemical storage tank at a Nippon Paper Group mill on July 26. The tank contained “white liquor,” a highly corrosive chemical used in paper processing, which was released in large quantities when the structure failed. Emergency crews are moving cautiously because the remaining tank structure is unstable and the chemical poses ongoing hazards. Federal chemical safety investigators are on site, and testing continues after some pollutants reached the Columbia River, though local air and drinking water remain safe, officials said on July 27.

Prepared by Emily Rhodes and reviewed by editorial team.