80 liters is only around 20 gallons. A fire truck would certainly have that amount on hand. If you heat an element enough, water that hits it will flash to steam. I think you could make a heating element robust enough to accomplish this but still light enough to fit on a truck. Now, the wisdom of suddenly producing 2700 cubic feet of superheated steam in a residential area -- maybe it's a bit too cumbersome and potentially dangerous to be worth it.