NTSB: Improperly Secured Lithium-ion Batteries Caused Cargo Vessel Fires

NTSB Press Releases

Published December 18th, 2025

Detected March 17th, 2026

Summary

The NTSB has released findings that improperly secured lithium-ion batteries caused two fires aboard the cargo vessel Genius Star XI, resulting in $3.8 million in damages. The investigation highlights the critical need for proper cargo securing and inspection to prevent thermal runaway events.

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What changed

The National Transportation Safety Board (NTSB) has released its findings on two fires that occurred aboard the cargo vessel Genius Star XI on December 25 and 28, 2023, attributing the cause to improperly secured lithium-ion battery energy storage system (BESS) units. The investigation determined that heavy weather caused the BESS units to shift, leading to internal damage and subsequent thermal runaway in three units, resulting in fires and approximately $3.8 million in damages. No injuries or pollution were reported.

Regulated entities, particularly those involved in the shipping of lithium-ion batteries, should review and reinforce their cargo securing procedures. The NTSB emphasizes the importance of adhering to the vessel's cargo securing manual, conducting thorough inspections of all securing arrangements, and verifying the proper seating of lashing belts and hooks. Failure to implement these measures could lead to similar incidents, potentially involving significant financial losses and safety risks.

What to do next

Review and reinforce cargo securing procedures for lithium-ion batteries.
Ensure adherence to vessel cargo securing manuals and approved lashing plans.
Conduct thorough inspections of all cargo-securing arrangements during and after loading.

Source document (simplified)

Improperly Secured Lithium-ion Batteries Cause Fires Aboard Cargo Vessel

12/18/2025

Cargo vessel Genius Star XI on February 24, 2024, after the fires.

WASHINGTON (Dec. 18, 2025) -- Heavy weather and an improperly secured cargo of lithium-ion battery energy storage system (BESS) units led to two fires aboard the 410-foot-long cargo vessel Genius Star XI as it was transiting the North Pacific Ocean on Christmas Day 2023, causing $3.8 million in damages.

Investigators determined that improperly secured lashing belts failed, allowing 41 lithium-ion BESS units to shift in the cargo holds, leading to internal structural deformation. This damage caused batteries in three of the units to enter thermal runaway, when a lithium-ion cell enters an uncontrollable, self-heating state that can exceed 572°F, causing the two fires within the holds.

After the first fire, the crew activated the vessel’s fixed carbon dioxide fire-extinguishing system and diverted to the nearest port, Dutch Harbor, Alaska, for assistance. The fire was extinguished. While en route to Dutch Harbor, a second fire occurred in another cargo hold on December 28. The crew cooled the affected area externally with fire hoses. The fire was confirmed extinguished when the Genius Star XI arrived at Dutch Harbor on Dec. 29. No injuries or pollution were reported.

The vessel had encountered gale-force northwest winds of about 26 knots, with gusts above 30 knots and combined seas and swells reaching 19 feet. These conditions caused significant vessel rolling and seawater to wash over cargo hatches.

NTSB investigators emphasized the importance of ensuring that cargo aboard marine vessels—particularly large stationary lithium-ion BESS units—is properly secured.

Crews should:

Follow the vessel’s cargo securing manual and approved lashing plan.
Thoroughly inspect all cargo-securing arrangements during and after loading.
Pay close attention to lashing belt hooks, wires, and chain falls to verify they are properly seated on D-rings and attachment points. Proper inspection and verification are critical to preventing cargo movement, structural damage to battery units, and potential thermal runaway events during heavy weather.

The full marine report is available on ntsb.gov.

To report an incident/accident or if you are a public safety agency, please call 1-844-373-9922 or 202-314-6290 to speak to a Watch Officer at the NTSB Response Operations Center (ROC) in Washington, DC (24/7).