LONGIVEW, WA (MyBellinghamNow.com) – We’re learning more about the chemical tank explosion that occurred at a Longview paper mill in May.

The U.S. Chemical Safety and Hazard Investigation Board (CSB) posted an update Friday, Aug. 28 to an investigation of the Nippon Dynawave paper mill conducted nearly a year prior. On May 26, one of the mill’s chemical tanks, known as G Tank, exploded, resulting in 11 deaths and the release of 900,000 gallons of caustic white liquor.

During their inspection of the mill in July 2025, CSB found that significant portions of the exterior shell of G Tank had thinned below the minimum safe thickness.

The inspection contractor recommended that the facility inspect and repair the thinned areas of the shell, warning that the tank could fail if the areas were not repaired.

Nippon Dynawave also conducted two inspections of the tank in 2025, noting the thinned areas.

Despite the tank’s volatility, normal operation conditions continued until its failure.

Kyle Findley, an attorney for the families of two workers who were killed as a result of the tank’s explosion, released a statement on the new information.

“Today’s report is a stark reminder of this tragedy that claimed 11 lives and devastated an entire community. The CSB’s finding that it was known that this tank was ‘not fit for service’ and posed a ‘high likelihood of failure’ from inspections months before is nothing short of alarming,” he said. “When safety inspections and recommendations don’t lead to action, danger becomes a reality that causes devastation to human life. We will continue to work tirelessly to ensure those responsible for this horrific accident are held accountable and their families receive justice.”

CSB issued its update days after the Washington state Department of Ecology announced its administrative notice of violations in response to the tank explosion.