By Deputy Chief Derrick Phillips
For decades, when a dispatcher toned out a structure fire at a “vacant” address, the implicit assumption among many crews was that the primary risk was limited to the building itself and the first responders tasked with extinguishing it. However, modern emergency services are facing a harsher reality, as the term “vacant” is increasingly a dangerous misnomer. While a building may be considered legally unoccupied due to a lack of active utility services, a lawful tenant or a functional purpose, it is rarely truly empty.
Major urban centers across the United States are grappling with a convergence of housing insecurity, mental health crises and economic displacement that has forced thousands of unhoused individuals to seek shelter wherever they can find it. Consequently, vacant buildings have become the new frontline of a humanitarian crisis, transforming seemingly routine defensive operations into high-stakes internal rescue missions.
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Homelessness and the squatting epidemic
The housing crisis in major American cities is visible on nearly every corner. When warming centers reach capacity and public spaces are deemed inaccessible, those without homes are forced to make drastic decisions regarding security and shelter. Abandoned warehouses, recently vacated single-family homes and closed commercial structures offer temporary refuge from the elements.
This phenomenon, commonly known as “squatting,” has evolved from scattered instances into a recognized trend for which fire departments must preplan. For the unhoused, these structures offer privacy and relief from adverse environmental conditions, but they also pose severe risks.
In the struggle to survive, these unauthorized occupants are often forced to use dangerous methods to keep warm or cook food. Lacking electricity or gas, they use improvised wood-burning stoves or unsafe heating fires directly on the floorboards. These fires, set within structures already characterized by neglect, frequently escalate rapidly. The fuel load is often compounded by trash and partitioned living areas constructed with flammable materials, such as cardboard and plastic sheeting.
The inherent dangers of vacant structure fires
From a firefighting perspective, a vacant building is a fundamentally compromised environment. They pose a unique set of hazards that are rarely present in well-maintained, occupied properties:
- Structural integrity: Without maintenance, roofs decay, floors rot and staircases become unstable. Previous fires may have already weakened the load-bearing components.
- Security measures: Owners trying to keep squatters out often board up windows and barricade doors with steel plates. These “fortress” properties trap occupants inside and severely impede firefighter access and ventilation.
- Removed infrastructure: Scavengers frequently strip these buildings of copper piping, electrical wiring and, crucially, fire suppression systems, ensuring any fire will have a massive head start.
- Booby traps and hazards: Unauthorized occupants sometimes create hazards to deter others, including holes cut into floors covered by debris or obstacles placed in stairwells.
In the news
The fire service does not have to look back far for evidence of this growing threat. Recent incidents in major cities have shown that the search-and-rescue mandate applies, even when a building appears deserted. Here in St. Louis, crews faced several significant fires in vacant structures in the past year, underscoring the persistent threat to life within these structures:
- Feb. 10, 2026: Firefighters responded to heavy fire at the 1400 block of North 13th Street, a three-story masonry building that once housed the city’s Greyhound terminal. Upon arrival, crews faced massive flames. Fire Captain Garon Mosby confirmed that one civilian was killed in the fire, and another woman found nearby was transported for treatment. Captain Mosby highlighted the complexity of the scene, noting that the building was a known encampment, with occupants partitioning a large room into several living spaces.
- Feb. 22, 2026: St. Louis crews arrived before 5 a.m. to a two-story brick, vacant building on North Kingshighway Boulevard with heavy fire showing on both floors. During an aggressive operation, firefighters rescued two people from the burning structure. Both were treated and transported, with one occupant listed in serious condition. Firefighters assisted a third person in safely exiting the building.
- Nov. 28, 2025: A fire at the historic Crunden-Martin warehouse complex south of downtown St. Louis highlighted the scale of firefighter risk. Unhoused individuals who escaped reported that one of their friends was missing. St. Louis Fire Chief Dennis Jenkerson confirmed that crews used heavy equipment to de-layer the rubble in a search that lasted days, pinpointing an area where they knew unhoused people had gathered to keep warm.
These events underscore the reality facing departments nationwide: A report of a vacant building fire is not a signal to abandon interior operations if a life hazard is suspected.
Preplanning and mitigation: A departmental necessity
Given the rise in unauthorized occupancy, fire departments must adapt their standard operating procedures (SOPs). Departments can no longer afford to assume a building is empty solely based on its derelict appearance.
Effective management requires a proactive approach:
- Marking systems: Many departments utilize marking systems (such as the standard “X” in a box) to denote vacant buildings that have been inspected and deemed unsafe for interior operations. These marks must be visible and up to date. The St. Louis Fire Department uses a virtual marking system in which each known vacancy is assigned a structural integrity rating and relayed to firefighters upon dispatch.
- Known encampment database: Departments should maintain data accessible to dispatchers and responding incident commanders listing “vacant” buildings that are known to have had recent activity or are popular sites for squatting.
- Community risk reduction: Fire departments must work with building divisions to enforce strict securement of vacant properties. This includes boarding up in accordance with municipal codes that require screws rather than nails, and potentially removing stairways or other internal access points in severely compromised properties. The St. Louis Fire Department takes it a step further by coordinating with the Building Division on emergency condemnation and razing of severely compromised structures.
- Aggressive size-up: Incident commanders must perform a thorough size-up that explicitly looks for signs of occupancy, such as forced entry, utility bypass (like extension cords running from neighbor properties), newly accumulated trash, or bicycles. This size-up should be performed during daily district familiarization surveys by response companies.
Final thoughts
The concept of a disposable property is outdated in the modern fire service. The human life inside a burning structure, whether a responding firefighter or an unhoused individual seeking shelter, is always the highest priority. The reality of homelessness in American cities has made vacant building fires some of the most complex and dangerous operations a department will face. Firefighters must enter every scene with a new default mindset that these buildings are occupied until proven otherwise. Anything less is a gamble with human life.
Note: The opinions expressed in this article are my own and are not the official position of my agency.
| WATCH: Fighting fires in booby trapped buildings
ABOUT THE AUTHOR
Deputy Chief Derrick Phillips is a 31-year St. Louis Fire Department veteran, serving as Operations Chief for the A-Shift, Executive Officer, and the Office of Homeland Security Commander. He holds a Master of Arts in Security Studies from the Center for Homeland Defense & Security at the Naval Postgraduate School and a Master of Public Administration from Arkansas State University. Chief Phillips also holds the Chief Fire Officer designation through the Center for Public Safety Excellence and is a graduate of the IAFC Fire Service Executive Development Institute.
