Columbine. Aurora. And now Boulder.

Driving the news: Colorado, which has endured some of America's most notorious mass shootings, now is the scene of the nation's second massacre in 7 days.

• The killing of 10 people at the King Soopers supermarket in Boulder — including the first police officer to arrive on the scene, Eric Talley, a father of seven — joins last week's rampage in Atlanta on an agonizing roster of inexplicable American tragedies.

The context: The pandemic year of 2020 had the smallest number of mass killings in more than a decade, according to an AP database.

• 2021 has already seen an awful reversal of that anomaly.

The Atlanta killings, which left eight dead, brought urgent new attention to the yearlong wave of violence against Asian Americans. The slaughter in Boulder renewed debate on gun control, which wasn't at the top of the agenda of the Democrats who rule Washington.

• Colorado State Senate Majority Leader Stephen Fenberg (D) told Brian Williams on MSNBC: "We have had a horrific year as a country, as a world. It had finally started to feel like things are getting back to 'normal.' And, unfortunately, we are reminded that that includes mass shootings."

In a preview of the renewed debate, Sen. Chris Murphy (D-Conn.) — who lives near Sandy Hook Elementary School, site of the 2012 killing of 20 children — tweeted: "This is the moment to make our stand. NOW."

• The latest: An injured suspect is being held. A handcuffed man, wearing only underwear and with a bloody leg, was led from the market. Police wouldn’t say if he’s the suspect.