Interesting the Koreans heaped sand on the inferno.
You need a ready supply of sand and a way to get it on the fire. You can’t drive it up to the fire with a front-end loader.
Sounds like a next generation Red Adair is needed.
The plant I used to work in made parts from magnesium.
Occasionally a part being machined would catch fire from from friction. There were barrels of some kind of black looking sand around to suck the heat away and to snuff out the air from getting to the part.