Washington paper mill chemical tank implodes, killing at least 1 and leaving 9 missing

At least one person was killed and nine others were unaccounted for Tuesday after a tank containing a corrosive chemical mixture ruptured and collapsed at a Washington paper mill, authorities said.

Nine people were injured in the collapse at Nippon Dynawave Packaging Co. in Longview, including one firefighter, officials said. Injuries ranged from minor to critical.

Officials said the response had shifted from rescue operations to recovery efforts.

"At the moment we are not aware of any rescues that are yet to be made," Cowlitz Fire and Rescue Chief Scott Goldstein said during a news conference.

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The cause of the collapse remained under investigation.

Emergency crews responded Tuesday morning after a tank containing a chemical mixture known as "white liquor" ruptured at the facility. White liquor is a corrosive chemical mixture used in the paper-making process.

Officials initially estimated the tank contained about 80,000 gallons of the substance, but later revised the amount to roughly 900,000 gallons.

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Authorities said approximately 90,000 gallons may still remain inside the damaged tank, which remains unstable and continues to complicate recovery efforts.

Several people suffered injuries ranging from minor to critical, including burns and inhalation injuries. One firefighter was among the injured.

U.S. Sen. Patty Murray addressed the community during the news conference.

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"I know there’s a lot of questions about how all of this happened and I want to assure you that we will all continue to pressure to get answers to those questions," Murray said. "This community deserves that."

Officials said there was no direct threat to the surrounding community.

The incident comes days after roughly 50,000 California residents faced evacuation orders tied to a hazardous materials emergency at an aerospace facility in Orange County.

On Tuesday, officials lifted the final evacuation order for residents in Garden Grove living near a damaged chemical tank at GKN Aerospace Transparency Systems that had previously been at risk of exploding after a tank containing highly flammable methyl methacrylate (MMA) overheated and became compromised. Officials said the immediate risk of explosion, fire or leak had passed.

The Associated Press contributed to this report.