Last June 28, a Volkswagen sedan making a left turn into a parking lot in Rensselaer, N.Y., was hit on the right side by a motorcycle. Two mothers in the front seat were almost unharmed. A 2-year-old sitting in a child restraint in the back seat received minor cuts from flying glass. But a 2-year-old boy sitting next to her, who was not protected by a child safety seat, died of a broken neck.

Less than a month later, a Chevrolet traveling near Maddox, Md., sideswiped a utility pole, went down a shallow embankment and overturned in a field. The young couple in the front, although not wearing seat belts, received only minor injuries. Their 2-year-old daughter, asleep in the rear and not in a safety seat, was thrown from the car and died of massive skull injuries.

The next day, a Dodge occupied by three adults and two infants, all in the front seat, was involved in a head-on collision in Addison, N.Y. The parents received only minor injuries. The babies they were holding in their arms were crushed into the dashboard by their parents' bodies and died of massive skull injuries.

Investigations by the National Transportation Safety Board concluded that all of the children killed in these accidents probably could have survived if they had been protected by the proper use of car restraints. And they are dramatic illustrations of why the board has embarked on a campaign to get 31 states to pass legislation requiring car seats and seat belts for children through the age of four.

Patricia Goldman, vice chairman of the NTSB, says that even in minor accidents such as fender benders, "the child is killed because he or she becomes a projectile. Their center of gravity is different. They are propelled forward." A 30-pound child involved in a 20 mph crash "is going to hit the first object it hits with the same impact as if you dropped it out of a third-story window.

"If you get a child nestled in your arms and there is an accident you're not prepared for, it's very hard to hold on. Either your arms are going to flail open from the impact, thus ejecting the child from your grasp and the child becomes a missile, or the child gets crushed between the adult and the dashboard," she added.

Last year, Virginia became one of the 23 states to pass legislation requiring restraints. As of Jan. 1, most children under the age of 4 must be secured when riding in a car. Failure to do so carries a $25 fine, and fines will go toward a car-seat loan program for people who can't afford to buy one. The D.C. City Council also recently passed child car-restraint legislation.

Maryland, however, has not. Legislators have been concerned about government intrusion into parents' personal business, as well as the impact of such a requirement on poor people. The state has, however, developed 35 lending programs with 1,400 car seats. Backers of restraints hope to get legislation passed this year.

States across the country have realized that car seats and seat belts can make the difference between a child living or dying in a car accident. Aware of the issues raised in Maryland, they are earmarking fines for lending programs and they are allowing parents to erase their fines with proof of purchase of a car seat. In some states, state troopers are carrying car seats in their cars so they can stop parents whose children are not secured and tell them about the restraints.

The NTSB is suggesting that children's car seats be given as Christmas presents. Last Christmas Eve, three babies were among five members of a Montgomery County family killed in a head-on collision. The fact that the collision was caused by a drunken driver was highly publicized. The fact that the babies were sitting in the back seat of a Volkswagen Rabbit on the laps of relatives was not.

The automobile is the largest killer of children between the ages of 1 and 5, claiming 600 lives each year, and injuring 40,000 more, far more than the number of lives lost or damaged in the airplane accidents the NTSB investigates.

While car seats won't save all children, the evidence is overwhelming that properly used restraints can help children ride out an accident in the car, instead of being thrown from it, thus reducing the extent of injuries. By drawing attention to the importance of child car restraints and by urging states to adopt approaches that educate parents, the NTSB is lending its expertise to a cause that will surely save lives.