Which of the following is NOT one of the three strikes against firefighters?

• A. Lower material mass
• B. Engineered shapes for structural elements
• C. Better insulation
• D. Higher material mass

Answer: (D)

Think about the factors that make fighting fires harder in modern buildings. The idea behind the three strikes is that certain construction traits create more danger for firefighters: lightweight construction with low thermal mass heats up and loses strength quickly; engineered shapes (like prefabricated or unusual structural members) can fail in predictable, dramatic ways under heat; and better insulation traps heat inside walls and ceilings, slowing ventilation and making hidden fires harder to detect.

Given that pattern, higher material mass doesn’t fit the same risk profile. Heavier, high-mass materials absorb and store more heat and tend to heat up more slowly, which generally delays failure and reduces some of the rapid, hidden hazards associated with lightweight or insulated construction. So the statement about higher material mass is not one of the hazards described, making it the correct answer. The other factors align with the typical hazards: lower mass means quicker weakening, engineered shapes can fail suddenly, and insulation can conceal fire growth and hinder firefighting efforts.