If you want to protect your city, then you have many options. Of course, your primary line of defense is a fire station. Like most of the civic buildings in the city, your fire station is composed of multiple parts: garages, fire trucks, dispatch towers, hazmat vehicles, helicopters and more. The bigger the station, the more it will cost you, so you need to be careful not to outspend the income you receive from taxes. However, having an awesome fire station doesn’t guarantee a fire-free city. If your roads are congested with traffic, then none of your trucks will arrive in time, even if the fire is only one block away.
You can also prevent major fires by carefully controlling how you zone. Avoid zoning large industrial areas. Industrial buildings tend to burn hot for a long time and create hazardous air pollution (especially the ones filled with fuel or chemicals). Small buildings contain less flammable materials than large buildings, so you can avoid big fires by keeping your city’s density low. Another zoning trick is to keep plenty of space between your buildings to keep an out-of-control fire from spreading too far.
If you are the type of player who would rather engineer your city for a catastrophic fire, then you’ll need to use the opposite strategy. Bulldoze the fire stations, zone heavily for high density industrial, and keep your buildings packed together in a tight cluster. I also recommend cutting back on your police force to encourage arsonists!
Fires go through several phases: smoking, blazing, spreading and burning out. Each of these phases triggers different simulation effects. Sims will race unharmed out of a smoking building, but if the building is blazing then the Sim will run out of it with their tiny heads on fire. If an ambulance isn’t on the scene, then the Sims will crumble into ash. (It may sound tragic, but for some reason, it consistently makes players laugh out loud.) During the spreading phase, the heat from the fire will cause nearby buildings to smoke, which will start the loop again. If the fire fighters don’t arrive in time then the fire will eventually consume all of the building’s flammable materials and the building will crumble into blackened rubble.
Every building type in the game has different fire characteristics. Wooden buildings burn quickly, brick buildings are almost fire-resistant and buildings with hazardous substances may explode, creating a giant fireball!