From this link:
Motor vehicle crashes are the leading cause of death among children in the United States. In the United States during 2002, 1,543 children age 14 years or younger died as occupants in motor vehicle crashes and about 227,000 were injured. Thats an average of 4 deaths and 622 injuries each day (NHTSA 2003a). Of the children age 4 years and younger who were fatally injured in 2002, 50% were unrestrained (NHTSA 2003a).
"For the childrrrrrrunnnnn" has been used as another excuse by liberals and "law 'n' order" types to expand the power of government at the expense of individual liberty.