Which of the following is considered a fatal funnel?

A fatal funnel refers to a location where individuals are vulnerable to threats while attempting to enter or exit a space. In this context, a door is considered a fatal funnel because it creates a narrow, defined passage that people must navigate when going in or out of a room or building. This limited space can be easily observed and targeted by an individual or group, thereby presenting increased risk during tactical situations.

When approaching a door, the individual is often in a position where they cannot effectively see or respond to threats on the other side until they fully breach the entrance. This makes it critical for security personnel to recognize and strategize around the risks associated with doors during operations, emphasizing the need for careful techniques to mitigate danger when entering or exiting through these structures.

While alleys, rooms, and corners have specific tactical considerations, they do not serve the same direct, vulnerable passageway function as doors do in the context of the fatal funnel concept.