On April 28, 2024, at 1031 local time, a fire started on board the uncrewed yacht Flagship while it was docked at an enclosed bay of a shipyard on the Miami River in Miami, Florida. Shoreside firefighters moved the vessel to a nearby sea wall, where they extinguished the fire. The vessel eventually sank at the sea wall. There were no injuries, and no pollution was reported. The Flagship was declared a total loss, valued at $5 million.
We determined that the probable cause of the fire on the yacht Flagship was the thermal runaway and explosion of the 24-volt lithium-ion battery bank due to the inoperable battery management systems, resulting in the practice of manually charging the lithium-ion batteries with a portable battery charger, which compromised the safe monitoring of the vessel’s lithium-ion battery systems.