Switching from an Offensive to a Defensive Strategy

By Frank Viscuso and Michael Terpak  

In their new book, Fireground Operational Guides (PennWell 2011), Frank Viscuso and Michael Terpak provide readers with a universal tactical worksheet that could be used at all structure fires and 70 operational “field” guides for incidents such as multiple-alarm structure fires (at various construction types and occupancies), water emergencies, natural gas emergencies, electrical emergencies, carbon monoxide investigations, outdoor fires, wildland-urban interface fires, vehicle fires, engine company operations, ladder company operations, hazardous material incidents, non-fire emergencies, general operations, and more. The operational guides featured in the book are designed to serve many purposes. They can be used as field guides, drill templates, standard operating procedure (SOP) formats, and study guides for firefighters interested in advancing their career to the officer level. The following is an excerpt from chapter 12, “General Operations.”

Offensive to Defensive Strategy

There are various reasons why an operation should be changed from an offensive to a defensive strategy (photo 1): Threat of collapse, rapid fire growth, truss roof involvement, and explosive contents within a structure are just some of the reasons why you may elect to go defensive. All circumstances revolve around conditions becoming worse and resources not being sufficient enough to get the job done. When the water supply, resources, and personnel on scene are not enough to keep up with a growing fire, and interior operations present great unnecessary risks for firefighters, the incident commander (IC) should be prepared to retreat and switch tactics. Any time a decision is made to change from an offensive to a defensive operation, the announcement must be clearly communicated to all fire personnel operating at and responding to the scene.


(1) Firefighters Gerard “Rod” Nardone and Matt Mitchell engage in a defensive operation.

Operational guide for switching from offensive to defensive 

The operational guide that follows provides necessary steps the IC should take when changing from an offensive to a defensive strategy. Always remember that it is better to go from an offensive to a defensive strategy too soon rather than too late. When it comes to firefighter safety and fireground survival, there is no room for hesitation.

1.     Announce a move to defensive operation via radio.
  • Have your dispatcher announce a change in tactics from offensive to defensive, and order all personnel operating within the structure to evacuate and meet at the command post (or another designated location).
2.     Sound the evacuation tones and air horn.
  • Have your dispatcher send a designated evacuation tone over the radio.
  • Have apparatus drivers activate their air horn four times to signify evacuation of the structure.
3.     Request additional alarm(s).
  • Request an additional alarm and necessary resources if you do not have enough of on scene or in staging to handle the change in tactics.
4.     Conduct a personnel accountability roll call (PAR).
  • Along with your accountability and safety officers, account for all personnel to ensure they have made it out of the structure. Have your dispatcher call the officer of each company to confirm all personnel are accounted for. (See the following example.)
         Dispatcher: “Engine 1.”
         Engine 1 officer: “E-1 officer, ALL members are accounted for.”
         Dispatcher: “Engine 2 officer.”
         Continue calling units until all companies/members are accounted for.
  • If members do not respond, activate the rapid intervention crew (RIC).
         The RIC should follow the “Operational Guide for the RIC.”  
5.     Readjust your Incident Management System (IMS) to reflect the new defensive operation.
  • Establish divisions on all four sides (A, B, C, and D).
         Do this after you conduct a PAR and account for all members.
6.     Establish your collapse zone(s). 
  • Walls collapse in three general manners:
         90-degree-angle collapse: This is most common and is similar to a falling tree. The wall falls straight out, and the top hits the ground at a distance equal to the height of the wall.
         Curtain-fall collapse: Generally occurs with a masonry wall. It collapses like a curtain dropping from the top, creating a pile of debris at the base of the wall.
         Inward/outward collapse: A wall leaning inward may not necessarily fall inward. The lower or upper portion may slide or “kick” outward.
  • The collapse zone itself should be as wide as the structure and one and a half times the height.
  • Take construction materials into consideration.
         Ordinary and heavy timber buildings = two times the height of the structure.
  • Use caution/barricade tape to clearly mark the edges of the collapse zone.
  • When established, collapse zones must be maintained during and after the incident, during the investigation, and until the structure is examined by an engineer.
  • Assign additional safety officer(s) to cover all four sides.
  • If you haven’t already, call for the response of the utility companies to shut off the gas, electric, and water to building from exterior locations, away from structure.
7.     Monitor for signs of collapse.
  • Depending on the height of the structure and its building features, set up a number of surveyor transits to detect an early structural movement from walls, church steeples and bell towers, water tanks, and so on.
  • Consider the following when determining collapse potential:
         Fire size and location
         Heavy fire for an extended period of time
         Pieces of the building falling off
         Cracks in walls
         Leaning or bowing walls
         Building age and condition
         Faulty/poor construction
         Foundation failure
         Extraordinary loads
         Lack of water runoff
         Sagging floors or beams
         Spongy roof or floors
         Previous fires at this location
         Explosions, flashovers, or backdrafts
         Water and/or smoke pushing through solid masonry wall
         Smoke through mortar joints
         Accidental cutting of structural support members
         Lightweight construction components
         Extreme weather conditions
         Fire reaches the truss roof
         Unusual noises (creaking)
         Any combination of causes
  • Firefighters should be mindful of the condition of the parapet, canopy, marquee, cornice, floors, and roof.
  • Constantly monitor for secondary collapse from the existing structure or collapse and failure of any surrounding exposure buildings.
  • Note: If collapse occurs, follow the “Operational Guide for Structural Collapse.”
8.     Set up master streams (ground monitors, deluge guns, large-diameter hoselines, and so on).
  • If the roof is still intact, aim the streams up, through windows, into involved ceilings.
  • If the roof has burned away, use elevated streams and aim down onto the fire.
  • If possible, position and secure unmanned master streams outside the collapse zone.
9.     Secure an additional water supply (from another source or water main).
  • Whenever possible, do not use the same water main when additional water is needed.
10.    Protect nearby exposures.
  • Do everything in your power to protect exposures from collapse, radiant heat, water runoff, and so on.
  • Evacuate exposures, if necessary.
11.     Assign a brand patrol. (This will depend on the building’s contents, height, and construction.)
  • Use a minimum of one engine and a ladder company.
  • Position downwind to track and extinguish flying brands.
12.     Rotate personnel frequently.
  • Establish emergency incident rehabilitation
         Follow the “Operational Guide for Emergency Incident Rehabilitation.”  
Fireground Operational Guides is available at pennwellbooks.com.
Deputy Chief Frank Viscuso, a 25-year veteran of the fire service, is a member of the Kearny (NJ) Fire Department. He is a certified New Jersey Fire Instructor and co-founder of FireOpsOnline.com. Frank is the author of the book Common Valor: True Stories from New Jersey’s Bravest, and co-author of the book Fireground Operational Guides.
Deputy Chief Michael Terpak, a 35-year veteran of the fire service, is a member of the Jersey City (NJ) Fire Department. He is the founder of Promotional Prep, a New Jersey-based consulting firm designed to prepare firefighters and officers as they study for promotional exams. He has authored the books Fireground Size-Up, and Assessment Center Strategy and Tactics and has co-authored the book Fireground Operational Guides.

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