Could have been as simple as crew not knowing until it was too far gone. You'd be surprised at the obliviousness of people.

Have you ever seen large tire fires? If there's no danger to other nearby structures etc...the FD usually let them just burn themselves out while they monitor. So if there were the li-on batteries combine that with all the new rubber tires, nothing onboard that boat could handle putting out the fire especially if it wasn't detected until it was too late. 

Many metals can burn if they get hot enough, and you cannot smother them. Sometimes fire suppressants can make the chemical reaction even worse, or even cause it to explode. Firefighters are not chemists.