Crashworthiness is one aspect of vehicle safety (the other being accident avoidance equipment). It deals with protecting drivers and passengers in the event of a collision. Crashworthiness features include seatbelts, air bags, roll bars, side impact bars, and "crumple zones." Vehicles may be uncrashworthy due to manufacturing defects (e.g. an air bag that does not fully inflate) or design defects (e.g. a roll bar that is not placed in an appropriate location). Vehicle manufacturers are responsible for the crashworthiness of their cars, trucks, and SUVs whether they are aware of potential safety hazards or not.