The causes for 131 fatal crashes of lap-shoulder belted occupants were analyzed for accident avoidance opportunities. Fourteen crash scenarios were determined to depict the situation and circumstances of the accidents. Each scenario is discussed in relation to crash type, driving action or behavior, inadvertent error, and influencing factors associated with crash causation. Nearly a third involved a rapid, unpredictable onset by reckless action or mistake by another vehicle. The others were single-vehicle crashes caused by excessive speed, aggressive driving, or drifting and multivehicle crashes related to driving errors or other factors. Some involved right-of-way violations at an intersection, loss of control on wet roads, impact of a stationary vehicle, and lane changing. Based on these scenarios, concepts for crash avoidance are discussed.