There is actually no way to 'put out' thermal runaway Li-ion batteries chemical fires. They have to be left to burn out which can take days and produces immense heat and toxic chemicals.

There is speculation that batteries undersides were scraped as the EVs were loaded onto the boat, damaging a battery underside.

A useful youtube shipping channel and discussion of this latest incident:

https://youtu.be/lEsO--Z2d2E

tldr:

- Li-ion batteries on fire cannot be put out with water and need special stuff... "often not to hand" on ships like this. Ships carrying hundreds of EVs

- IATA of the sea plans to get around to add new safety measures "next year"

Seems like they were basically crossing fingers until now? I guess ships go down slowly and people usually don't die, and I guess they don't care that much about dumping 2000 tons of fuel oil into oceans on occasion. Cheaper than firefighting measures...