We have not seen any battery boxes with fittings for a hose. Fire Departments are having to play catch-up with EV's and trying to find an effective way to put them out without putting tons of water on them.
I know someone said before using a "Fire Blanket" to put it out. Just to clarify that those are best for regular car fires, not EV. You need to cool down the batteries as fast as possible to prevent an explosion. Putting out a car fire is 1 thing but keeping the batteries cool is the big concern with EV's.
I'll link 2 videos, this one is what a fire a fire blanket does (Suppress a fire, not extinguish it) and is just a "Tool" in the arsenal. For as much time as it takes to do everything they did, a trained department could put that out in as much time. Again, the issue is keeping the batteries cool. Blanket Video -
This is 1 way to keep things cool but isn't always feasible for small rural departments but again is like using a piercing nozzle to keep the batteries cool.