John Ploetz, a retired truck company owner, Vietnam vet and American Legion commander, died on a Sunday afternoon just before Christmas, on a road outside of Cambridge, killed by a woman with a record of texting and driving, who blew a stop sign and crashed broadside into his vehicle.

That woman, Heidi L. Butau, was sentenced earlier this week. She will serve 10 days of a 90-day sentence for the misdemeanor with which she was charged. Why just a misdemeanor when a man is dead? Chisago County Attorney Janet Reiter said prosecutors lacked evidence that Butau was using her phone at the time of the crash because a deputy on the scene failed to collect the cellphone immediately. By the time it was obtained — two weeks later — any potentially incriminating data had been wiped.

The incident highlights the fact that this society has yet to regard what commonly is referred to as “distracted driving” with the seriousness required for an offense that now plays a role in one out of every four vehicle crashes, according to the National Safety Council. You see these drivers every day on their phones — gabbing, texting, updating Facebook, posting Instagram stories, all while at the wheel of speeding, two-ton vehicles. You may well be one of them. At least 40 percent of drivers are.

Why do drivers take such chances? Maybe the first problem is the language used. “Distraction” sounds so small, so harmless, so lacking in ill intent. But misusing a cellphone while driving is none of those things. It’s a willful act of recklessness that poses a danger — sometimes lethal — to the driver and others.

From the collection of evidence, to the charges filed, to the penalties imposed, the legal system should be committed to treating this offense as the act of endangerment that it is. The change must start with drivers, convincing them that they are not the masters of multitasking they imagine themselves to be. The fact is, studies have proven again and again that drivers are incapable of being fully aware of their surroundings while on the phone, whether texting or conversing.

When the brain is overloaded with information, it starts to juggle and prioritize, employing what researchers call “inattention blindness.” Simply put, your eyes may be on the road, but if your brain is engaged on the phone, you’re not “seeing” as much as you think you are. The field of view literally narrows, and drivers become more likely to miss important visual cues. Like a stop sign. Or a pedestrian crossing. Or that car crossing the intersection. The worst part? They don’t know they are not seeing everything until it’s too late. Every time they don’t have an accident, the behavior gets reinforced.

Butau, 45, is among those drivers who appear to have less than a healthy respect for the complex task that is driving. She’d already been convicted eight times in Minnesota for speeding, once for running a stop sign. And oh, two priors for texting while driving — one just a few weeks before she plowed into Ploetz’s vehicle.

Don’t make the mistake of thinking that could never be you. Science says otherwise. The next time you’re tempted to reach for that phone, think of Joanne Ploetz. The day after the crash, she came home to find someone had deposited a plastic bag on her doorstep, containing the broken dentures and billfold of her husband of 48 years. She never got to say goodbye. At the sentencing, she told Butau, “In an instant you took this wonderful man from us. I am not sure what was so much more important than seeing the stop sign.”

Nothing was more important, Mrs. Ploetz. Nothing could be.