In May 2026, the collapse of a chemical tank at NDP, Nippon Paper Industries’ US subsidiary, killed 11 people and injured 8. A preliminary investigation report released by the CSB in August points to lax safety management behind the decision to ignore the warning and continue operations.
A chemical tank collapsed in May 2026 at Nippon Dynawave Packaging (NDP), Nippon Paper Industries’ US subsidiary, killing 11 people at the site and injuring 8. Moves toward damages and environmental litigation are under way locally. The CSB released its preliminary report on the accident in August.
According to the CSB report, an inspection conducted approximately 10 months before the accident found that most of the collapsed white-liquor tank was below the minimum required thickness and explicitly stated that it was in a condition that could not be kept safe. Nevertheless, NDP did not repair the tank and continued operating it.
The company also conducted inspections in October 2025 and February 2026, but took no measures such as an internal inspection of the tank, repairs, suspending operations or reducing operating conditions. On the day of the accident, a process problem caused the fill level to reach 90%, and the tank, which had reached the limit of its structural strength, ruptured.
The CSB plans to determine why the tank was left in operation and has indicated that it will deepen its investigation into the lack of an underlying safety management system.