On Sept. 28, 2016, there was a shooting on the playground of Townville Elementary School in South Carolina. A teacher and two students were shot, one of whom — a 6-year-old boy — later died. National media coverage was limited, a sad sign of how accustomed the country has become to these shootings, especially when “only” one child dies. But the damage from what happened on that playground in 12 deadly seconds extends far beyond those killed or wounded. That should further prod efforts to combat gun violence.

A searing examination by The Washington Post of the children who witnessed last fall’s shooting revealed scars and struggles. Recurring nightmares, inability to focus and fear of leaving home were just some of the symptoms. These elementary school children are suffering post-traumatic stress similar to that of combat veterans returning from war. In an article filled with heartbreaking details, one stands out: that balloons were banned at the spring school festival because, as the principal observed, “Noises are different now.”

Even more heartbreaking is that the students of Townville are not alone. An analysis by The Post found that beginning with the shootings at Columbine High in Colorado 18 years ago, more than 135,000 students attending at least 164 primary or secondary schools have experienced a shooting on campus. That doesn’t include other incidents — accidents, after-school assaults, suicides — in which children have been exposed to gun violence. The damage extends to parents, grandparents and siblings forced to cope with trauma. Imagine having to reassure your 7-year-old son that he couldn’t have done more to protect a friend gunned down, or not knowing if your daughter will ever recover from what she witnessed in those 12 bloody seconds.

This week marks the first anniversary of the deadliest shooting in the country’s history, when 49 people were killed and more than 50 injured at a nightclub in Florida. Since then, there has been little progress in adopting national common-sense gun control laws — such as expanded background checks — that a majority of the American public supports and that would help keep guns out of the hands of the wrong people. The gun lobby, believing it has a receptive audience with Republicans in control of Congress and the White House, is pushing an extreme agenda that would deregulate the sale of gun silencers, federally mandate concealed-carry laws in every state and even eliminate gun-free school zones. Countering the gun lobby is a growing grass-roots movement for gun control that has claimed some victories on the state and local levels in closing loopholes and strengthening protections. That is encouraging, and we wish them more success because far too many children already have died — or been traumatized — by gun violence.

Editorial by The Washington Post