Fire

Each day the city makes one roll for a new fire. The chance scales with how many structures you have, so a bigger city sees more fires on average even though every individual building is still very unlikely to burn on any given day. Fires start where people cook, heat and wire things: trees and park furniture never ignite on their own, they burn only when a fire next door reaches them. The base monthly rate on this page is taken from FDNY records. A heatwave event multiplies that base rate by five for as long as the event lasts, so summer is more dangerous than winter.

Once a building is on fire, its fire intensity climbs one step per day. A building collapses into rubble that you will have to demolish after three steps per floor, so a house is lost in three days while a tower holds out for two weeks. Every active fire also gives each building it touches its own small chance to catch each day: one percent for an ordinary structure in normal weather, five percent during a heatwave, and more still in a gale on the windy map. Trees are the exception. A canopy catches twenty times as readily as a house, so a fire that reaches a park walks from tree to tree, creeping on a calm day and racing through the whole park in a heatwave. Spread is independent of the fire department response, so a long-burning fire can seed new fires even before the brigade arrives.

How fire departments actually respond

Every fire station hires firefighters from the local workforce. The whole-city response capacity each day is the integer division of your total firefighters by the per-incident floor on this page. The standard reference for that floor is NFPA 1710, which calls for 15 firefighters per structure fire. So a city with 14 firefighters has zero response capacity, because 14 divided by 15 rounds down to zero. Hire one more and the same city goes from “no response” to “one response per day” in a single step.

Each available response is dispatched to a fire that has been burning long enough to need help (currently more than eight days), regardless of which station the firefighters came from. There is no priority queue across simultaneous fires: if more burning buildings qualify than the city has response capacity that day, the excess go unattended. Rolling the trucks costs the fire budget only a small marginal amount per incident, the diesel, foam, and equipment wear listed on this page. The expensive part of a fire is never the response: it is the building. A fire the brigade cannot reach in time burns down to rubble you have to demolish, and you lose the structure along with the rent or taxes it was paying. Departments below the threshold still draw their salaries and fleet-maintenance bills every month, so you are paying for trucks that physically cannot roll out.

Standing monthly costs

This page lists the firefighter monthly salary and the per-truck fleet maintenance. Both bills land every month whether your trucks are on call or sitting idle. Each station keeps a pump engine and a ladder truck, so its maintenance is charged for two apparatus. Building more stations than your workforce can staff buys you idle trucks that still cost money to keep ready.

That ranking mirrors how real departments spend. In the FDNY’s Fiscal 2025 budget, personnel are consistently more than 85 percent of the total, with vehicle and equipment maintenance a much smaller recurring line. Salaries are the cost that should dominate your fire budget; the per-incident dispatch charge is deliberately small.

Your levers

Build stations, which opens hiring slots.
Fill those slots from your adult workforce.
Build a City Hall, which improves fire department coordination across stations.
Watch the firefighter count as your city grows. Dropping below the per-incident floor is the most common quiet failure. Your population grew, your building count grew, and the daily fire roll started landing on buildings the department cannot reach.

Parameters

Fire response cost

$500

Marginal cost of rolling one engine to one fire for one day: diesel burned idling at the pump (~$75-150), Class A/B foam and other consumables (~$150), and hose and equipment wear that must be replaced after a working fire (~$200). Charged per engine dispatched per day, so a stubborn blaze that keeps crews on scene for a week costs more than a fire knocked down on the first morning. Personnel are billed separately as firefighter salaries, and the real economic loss from a fire is the damaged building itself (if it is not saved it collapses into rubble you must demolish), not this dispatch cost.

⚠️ Source pending

Fire truck monthly maintenance

$1,500

Monthly preventative maintenance for one heavy fire apparatus: hydraulic and pump testing, oil changes, and routine fleet upkeep (~$18,000/year per truck). Charged per apparatus every month a station stands. Each station keeps one pump engine and one ladder truck, so over-building stations you cannot staff still drains the budget on idle trucks.

⚠️ Source pending

Fire rate month

0.022

Monthly probability of a random structure catching fire on its own. Fires start where people cook, heat and wire things, so only structures roll: a tree, a fountain or a picnic table burns only when a fire next door reaches it (see FIRE_SPREAD_DAILY_CHANCE). Fire departments respond to these incidents and prevent buildings from burning down.

Source: Fire Department of New York City (FDNY)

Fire spread daily chance

1

Daily chance that a burning building sets fire to ONE ordinary structure it touches; every neighbour rolls on its own. Fire crosses a property line through radiant heat, embers and shared walls, and in a city of masonry and fire-rated construction that is slow: the great majority of structure fires never leave the building they started in. The chance is multiplied by the neighbour’s blueprint flammability — a tree’s canopy catches 20x as readily as a house, so fire walks through a park but mostly stays put in a street of houses — and by the weather: 5x in a heatwave, up to 4x more in a gale on the windy map, capped at a certainty.

⚠️ Source pending

Minimum firefighters per response

15

Minimum number of firefighters required to respond to a single structure fire alarm. A station fields one engine per full crew it has on shift, so a 15-seat neighbourhood house works one fire at a time while a 40-seat headquarters can work two — or send both engines to the same blaze and put it out twice as fast. A house that cannot muster one full crew fields nothing.

Source: NFPA Standard 1710

Firefighter monthly

$5,164

The monthly salary paid to each firefighter. This amount is deducted from the city’s funds each month for every active firefighter.

Source: FDNY