How will they put out the fire if water causes an explosion?
sand or let it burn out are the only options, however the article says no magnesium was involved it was rags and chemicals but no mag.
AFFF (spoken as A-triple-F) = Aqueous Film Forming Foam
or
PPK - Purple Potassium Power
or
CO2 - Carbon Dioxide
Used in the USN circa 40 years ago for Class D (burnable metals) fires.
We probably have some new solutions that don't use water.