Structural Ops

Author(s): Ben Klaene, Russ Sanders Published on September 1, 2009

The Church Problem
Why blazes in houses of worship can be especially challenging for firefighters.

NFPA Journal, September/October 2009

When fighting fires in churches, as in other complex occupancies, three important considerations firefighters must deal with are pre-incident planning; truss construction, which adds an additional hazard to any structure fire; and the potential pitfalls that arise when changing from an offensive to a defensive strategy, something that is common with church fires.

 


Boston firefighters spray water on the remains of a church in the Jamaica Plain neighborhood in 2005.

FROM THE ARCHIVES

July - August 2009
Knowing a building’s intended use is key to developing strategy and tactics

May - June 2009
Why you need to know a building’s intended use

March - April 2009
Truss construction can put firefighters at risk

January - February 2009
Estimating structural stability

November - December 2008
Strategy and tactics applied to large area fires in urban areas

September - October 2008
Tactics to consider when protecting exposures

July - August 2008
The extinguishment tools of the trade

The potential for large loss of life and property at church fires requires the development of an incident action plan that applies a thorough risk-versus-benefit analysis. Pre-incident planning is crucial to answering many vitally important questions in advance. For example, what is the maximum occupant load and where are the exits located? What and where are activities other than religious services conducted? Do these activities include occupants with special needs? What is the required rate-of-flow for large open areas within the church? What is the height of the building and collapse zone distance?

Calculating the rate-of-flow and knowing the structure in advance, then determining on arrival the occupied status of the building and the extent of involvement, will allow the incident commander to make the critical offensive/defensive decision.

In occupied places of worship, fires are generally quickly observed, and an alarm is usually transmitted before the fire can gain much momentum. When confronted with a limited fire and a large number of occupants, firefighters usually employ offensive tactics to evacuate the building while simultaneously controlling the fire.

A different approach is often necessary in unoccupied churches, where a fire may spread undetected until a passerby reports flames visible from the exterior of the building. Most churches consist of large open areas, and the false space between the ceiling and the roof of a church can be immense. Although this area is typically supported in older churches by large-dimension lumber, modern churches more commonly use lightweight truss construction that collapses faster when involved in a fire. In the past 20 years, three church fires where wood truss roofs collapsed resulted in multiple firefighter line-of-duty deaths.

A church’s large open areas, combined with the possibility of a roof collapse, often require a defensive attack once the fire has gained enough momentum. Due to the height of many churches and the likelihood of a catastrophic collapse, defensive operations can be difficult and require a large collapse zone.

Often, firefighters initially apply offensive tactics and switch to a defensive mode once they know the extent of the fire. This switch is very challenging, especially if multiple hand-held fire streams are used during the initial attack.

An early morning fire in an unoccupied church in Louisville, Kentucky, in January 1986 illustrates the problem. With the church empty and heavily involved in fire, the incident commander decided to switch from an offensive to a defensive attack. Firefighters, who thought they could quickly mop up a small exposure fire in the front of the building, advanced one of the offensive lines into the collapse zone. As they did, the front of the church partially collapsed, trapping the crew. The firefighters were pulled to safety, but the outcome could have been very different. This near-tragedy serves as a reminder of the importance of shutting down and disconnecting unused hand lines during defensive operations.

In church fires, as in fires at any large, complex structure, occupancy plays a major role in determining strategy and tactics. However, the first operational priority when formulating an incident action plan is always life safety. As NFPA 1500, Fire Department Occupational Safety and Health Program, states, "activities that present a significant risk to the safety of members shall be limited to situations where there is a potential to save endangered lives."


This column is adapted from the author's book StructuralFireFighting, available online or (800) 344-3555.