They were the best of us.

A doctor. A police officer. A pharmacy resident.

They chose to save lives for a living.

They were our city’s future, as well.

Dr. Tamara O’Neal was 38. Officer Samuel Jimenez was 28. Dayna Less was just 25.

We are losing our best and our future to guns and a culture of violence. Outside war zones, nobody kills like Americans.

EDITORIAL

In an editorial yesterday, written even before these three good people had died after being shot at Mercy Hospital, we wrote about the stupidity of America’s gun laws. We were angry then, and we’re angry still.

But enough.

Today, on the eve of Thanksgiving Day, we would rather remember and honor them — the doctor, the cop and the pharmacy resident. If nothing else, their families should know that a city is brokenhearted.

Dr. O’Neal was an emergency room physician who, according to her father, “loved the action.” She became a doctor, in part, because a professor once told her she didn’t have what it takes to be a doctor. She proved him wrong. She loved dancing, and outings in Chicago with her young nieces and nephews. And on Sundays, she was her church’s choir director.

One Mercy Hospital colleague told the Sun-Times that Dr. O’Neal was “simply one of the most fascinating, hardworking persons.”

Another colleague wrote in a tweet: “Tonight, I broke down in front of my coworkers when we lost her, and tonight I held hands with her mother in prayer. Tonight, we lost a beautiful, resilient, passionate doc.”

Who becomes a doctor? Somebody who cares.

Officer Jimenez had been on the police force for just a year and a half, but he was the “real police,” a fellow officer told the Sun-Times. He loved his job, and nobody expected anything less when he ran toward the gunfire at Mercy. As Police Supt. Eddie Johnson later explained, that’s what “heroic officers always do.”

Officer Jimenez was a family man, too, leaving behind a wife and three children.

Please know, children, that had it not been for your father’s courage, even more people might have died. The gunman might have kept firing.

Just hours after Officer Jimenez was shot at Mercy, as it happens, another Chicago police officer was shot in the vest during a confrontation after making a traffic stop a few miles away. Had it not been for the protective vest, we might be mourning that officer’s death today, too.

Who becomes a police officer?

Somebody willing to do the most dangerous job in town so as to keep us safe.

Dayna Less, the pharmacy resident, was seven months away from marrying her teenage sweetheart. They had met at a church camp when she was 9 years old, and they had been through a lot together.

Ms. Less suffered terrible headaches as a teenager, which led to major surgery, and her boyfriend stuck with her, making her laugh. The wedding was going to be a big one, in Lansing, with almost 500 people.

“She was good at her job because it helped others,” a member of Ms. Less’ family said in a statement. “She was forged in her own adversity, which made her the strongest person I will ever know.”

Who becomes a pharmacist? Somebody who wants to heal others.

As for the killer, we have nothing to say except this:

How did a man who once threatened to shoot-up the Chicago Fire Academy, and against whom a woman had once sought an order of protection, obtain a license to legally carry a concealed weapon? How was he allowed to own any gun at all?

As a city and state, we have to answer to that.

We are losing our best and our future. We can let it happen, or we can do something.

Send letters to: letters@suntimes.com.