More fire fighters have been killed in ________ construction.

• A. Heavy Timber
• B. Fire-Resistive
• C. Ordinary
• D. Wood Frame

Answer: (C)

Understanding how building construction affects fire behavior and structural stability helps explain why ordinary construction has historically been a greater danger to firefighters. Ordinary construction uses interior wooden framing and often contains concealed void spaces where fire can spread unseen. As the fire intensifies, those wooden members can weaken and fail, leading to rapid collapse of floors and roofs and trapping firefighters inside or preventing escape. The exterior walls may remain standing, giving a false sense of safety while the interior structure fails. By contrast, heavy timber has larger, more massful members that char and maintain strength longer, fire-resistive construction uses noncombustible materials that resist fire, and wood-frame structures, while also hazardous, involve different fire dynamics. The combination of combustible interior framing and concealed passages in ordinary construction makes sudden collapse more likely, which is why more firefighters have been killed in that type of construction.