For this mission, you’ll need a Firetruck. Press R3 when inside to begin.
The goal of this mission – my favorite – is to put out fires. However, you are on a time limit, therefore, you must go fast and ram into cars for some ridiculous things to happen. Once at the fire, press and Circle to shoot some murky water from the hose; use the Right Analog Stick to aim onto the fire.
The main reward, other than money and mayhem, is the Flamethrower icon at your hideout. To get it, you’ll need to put out twenty fires on Portland, twenty on Staunton, and twenty on Shoreside.