Images of the deadly Schoharie, New York, crash in which twenty people were killed, show a passenger compartment intact and the vehicle upright.
Seventeen of those killed were riding in that part of the vehicle.
If they were not wearing seat restraints, the cause of death would likely be attributed to deceleration injuries.
News reports suggest that the vehicle was traveling around 60 MPH when it passed through the intersection and entered the parking lot.
That speed amounts to approximately 88 feet per second.
If the initial impact was with parked cars, perhaps slowing the vehicle speed by half, the relative speed of unrestrained passengers moving forward would still have been around 40 feet per second.
Those in the rear of the passenger compartment would become missiles and those in the front would be subjected to the weight and force of these passengers as they impacted the front of the space.
Two critical body areas are known to be especially susceptible to deceleration injuries: the brain and the pericardium.
Seat restraints would likely have prevented or lessened the free movement of passengers inside the passenger compartment though some deceleration injuries could still occur.
Seat restraints save lives.