Which of the following is NOT an exterior hazard to identify before advancing lines or ladders?

• A. Gas meters or lines.
• B. Downed power lines.
• C. Unstable ground or debris.
• D. Interior flames visible through windows.

Answer: (D)

Identifying hazards before advancing lines or placing ladders focuses on what could harm you outside or at the exterior of the structure. Gas meters or lines are an exterior hazard because a rupture or leak there can fuel a blast or fire as you approach. Downed power lines are another exterior risk, since contacting them or the ground around them could energize equipment and surfaces. Unstable ground or debris threatens footing and ladder stability, making it an exterior concern to assess before moving in. Interior flames visible through windows, however, indicate fire conditions inside the building rather than outside. They signal interior hazards and the need for interior operations, but they aren’t hazards you identify on the exterior side before advancing lines or ladders.