Unbuckle during a commercial flight, an attendant scolds you. Drive without wearing your seatbelt, an officer tickets you. Put your child on a school bus unequipped with seatbelts, though, nothing happens. The bus driver simply pulls away with squeak of the doors and a puff of diesel.

It’s a stunning image in this era of safety innovation, and it happens every day.

Four teenage girls were killed Monday when their school bus plummeted off an interstate in Huntsville, Ala. Dozens more were injured, with rescuers extricating a tangled mass of passengers from the wreckage. “They were thrown all over the bus,” was how the scene was described.

While it’s unclear whether seatbelts would have changed Monday’s tragedy, the image of the crash – students flying from their seats as the bus falls – should alarm parents and educators alike, and revive the evergreen argument of whether its time to equip standard-sized school buses with seatbelts.

The debate occurs in Maine often. “It comes up almost every legislative session,” said Harvey Boatman, director of school transportation for the Maine Department of Education.

New York mandated school bus seatbelts in 1987. New Jersey, Florida and California have similar legislation. Maine does not, though Boatman said some districts do elect to purchase buses equipped with seatbelts.

Buses do have exemplary safety records. Boatman pointed to the design principle of “compartmentalization” – think of a school bus as an enveloping egg crate – as a reason seatbelts are not mandated. Capacity is also a concern, he said, as seatbelts could reduce the amount of passenger space in a school bus by 20 percent.

Plus, Boatman added, school buses are already perhaps the safest vehicles on the road today.

Data supports his statement. Child fatalities on buses average between seven and 10 yearly, according to national studies. By comparison, said Boatman, children killed in other school-related travel number about 800 annually.

And in 2002, a National Highway Transportation Safety Administration study said seatbelts do more harm, than help, in a crash. “Lap belts appear to have little, if any, benefit in reducing serious-to-fatal injuries in severe frontal crashes,” it said. “On the contrary, lap belts could increase the incidence of serious neck injuries and possibly abdominal injury among young passengers in severe frontal crashes.”

Critics, like the National Coalition for School Bus Safety, said NHTSA ignores the liability and preventative benefits of seatbelts, and relies too much on “compartmentalization” as preventative measure. The arguments are persuasive on both sides, yet the common-sense approach is erring on the side of safety, instead of trial and error.

Technology now allows people to walk away from horrific crashes. Seatbelts on aircraft can prevent a nasty lump during turbulence, but little else. On school buses, at least, seatbelts have the potential to save a life. There are few more compelling reasons to have them.

Safety should not be an option, especially for children.