The purpose of a crash investigation is to ______.

The purpose of a crash investigation primarily encompasses understanding what occurred during the incident by analyzing the totality of the circumstances. This involves looking at various factors such as the physical layout of the crash scene, vehicle positions, damage, environmental conditions, and any relevant traffic laws. By focusing on the overall circumstances, investigators can piece together a detailed and accurate account of the events leading up to the collision.

While determining fault is a component that may emerge from the investigation, it is not the sole focus—rather, fault is a conclusion drawn from the findings of the overall investigation. Engaging in interviews with those involved can be part of the investigation process, but it is not the primary goal; instead, interviews serve as a means to gather more information to support the holistic understanding of the incident. Therefore, the correct answer emphasizes the comprehensive approach taken in crash investigations rather than narrowing it down to specific aspects like fault or interviews.