A week after the assault-weapon killing of three and wounding of 13 at the Gilroy Garlic Festival, the incident has slipped from big national news to a blip in the annals of the nation’s mass shootings.

We should not let the deaths of 6-year-old Stephen Romero, 13-year-old Keyla Salazar and 25-year-old Trevor Irby be forgotten. Our elected leaders — especially in Washington — must stop domestic killings with weapons of war, rather than cast aside the carnage with mere expressions of sympathies.

Thoughts and prayers don’t cut it.

The solution is simple: Reinstate a national assault-weapons ban like the one we had from 1994 to 2004. The ban saved lives. When it was in effect, one study concluded, mass-shooting fatalities were 70% less likely to occur.

To be sure, mass shootings represent a tiny share of all shooting deaths in the United States. We have a gun problem in this country that needs to be addressed at multiple levels, including reducing the proliferation of weapons on the street.

But mass public attacks are becoming deadlier. There were four times as many people shot in mass shootings in 2017 than the annual average of the eight years prior, according to Everytown for Gun Safety, a national gun-control group.

Over the past decade, the six deadliest mass shooting incidents in America — Las Vegas, Nev; Orlando, Fla; Newtown, Conn.; Sutherland Springs, Texas; Parkland, Fla.; and on Saturday, El Paso, Texas — all involved the use of assault weapons. Assault rifles accounted for 86% of the total 501 mass-shooting fatalities reported in 44 mass-shooting incidents between 1981 and 2017.

Mass killings are shaking our nation, raising fears about school safety, the sanctity of our places of worship and the vulnerability of entertainment venues, whether it’s Las Vegas or Gilroy.

And they could easily be curtailed. While the nation can debate the merits of restrictions on handguns and rifles, there’s no rational justification for allowing AK-47s and other similar rapid-fire weapons on the streets of our cities.

If not for the bravery of the outgunned police at the Gilroy festival, who were fortunately nearby, responded immediately and risked their lives to attack the shooter with their sidearms, the Gilroy attack could have been much, much deadlier.

The good news is that since 26 were killed at Sandy Hook Elementary School in Newtown in December 2012, 45 states and the District of Columbia have enacted over 315 gun safety laws, according to the Giffords Law Center to Prevent Gun Violence. The trend has intensified since 17 students died in Parkland in 2018.

But only seven states, including California, and Washington, D.C., have some type of assault-weapons prohibition in place, according to Everytown. And, as the 19-year-old Gilroy shooter, who purchased his weaponry in Nevada, demonstrated, state laws are undermined when a neighboring state lacks similar safeguards.

This is a national problem that requires a national solution. And that national solution won’t come with Donald Trump as president and the National Rifle Association holding a firm grip on the Republican-dominated U.S. Senate.

The NRA’s fund-raising and political influence has been softening, in part because of mass shootings and in part because of its own internal turmoil. The 2020 elections provide an opportunity for gun-control advocates to take over the debate.

The tragedy last Sunday in Gilroy was preventable. All it would have taken was political will.