LITTLETON, Colo.—Evan Todd, then a sophomore at Columbine High School, was in the library on the day 19 years ago when Eric Harris appeared in the doorway, wielding a shotgun. Harris fired in his direction. Debris, shrapnel, and buckshot hit Todd’s lower back; he fell to the ground and ducked behind a copy machine. Harris fired several more shots toward Todd’s head, splintering a desk and driving wood chips into Todd’s left eye.

Todd listened for several more minutes as Harris and Dylan Klebold murdered their classmates, taunting them as they screamed. Todd prayed silently: “God, let me live.”

Then Klebold pulled back a chair and found Todd hiding underneath a table.

He put a gun to Todd’s head. "Why shouldn't I kill you?" he asked.

“I've been good to you,” Todd said.

Klebold looked at Harris. “You can kill him if you want,” Klebold told his teenage co-conspirator.

No one knows why—indeed, no one knows the “why” behind such violence—but that’s when Harris and Klebold left the library. Todd got to live.

Thirteen people did not, though. Today, that’s why Todd supports allowing teachers to have guns in schools. Teachers shouldn’t be required to be armed, he says, but if they already have a concealed-weapons permit, and they’re already comfortable using a gun, why not let them have it with them in school, the place they are most of the day, and the place where these attacks happen over and over again?

Today, Todd is a stocky, bearded manager of construction projects, and describes himself as a history buff. He grew up around guns, but after Columbine, he thought hard about whether easy access to them might have been what caused the shooting. No, he decided. “We've always had guns since the beginning of the founding of our country, but what we haven't always had are children murdering children,” he told me over coffee this week. “Something has changed.” Todd believes school shootings are motivated by a fundamental lack of respect for human life.

The way Todd sees it, “liberals like to control others and conservatives like to control themselves.” He glanced around the Starbucks where we were sitting. Statistically, he said, four people there were likely to have guns on them. Being near four guns might scare many liberals. Many conservatives, though, would want to be one of the four with a gun.

The gun debate is an odd one because, at some level, everyone agrees on what they want: No more Columbines. No more Parklands. Most people affected by the Columbine massacre can even agree on what definitely didn’t cause it. After the shooting, Columbine developed a reputation as a toxic school where jocks tormented “geeks” like Harris and Klebold. But it’s a stretch to say the shooters were pitiable outcasts, bullied until they snapped. In reality, they were budding little fascists who wore swastikas on their clothes and spewed racial slurs as they gunned down black classmates. Kumbaya circles wouldn’t have fixed that.

The Columbine Memorial in Littleton. (Kirsten Leah Bitzer)

But, nearly 20 years later, not even people in Littleton can agree whether the best way to prevent another Columbine is more guns or fewer. Todd’s experience—a 15-year-old whose brush with death-by-gun led him to respect guns more—helps to explain why there have been so few new federal gun restrictions since Columbine.

There have been at least 10 mass school shootings in the years since, which have claimed at least 122 lives. On Saturday, hundreds of thousands of young people will march on Washington to show just how much this disgusts them. They believe they will be the ones to end the most calcified cultural stalemate of our time: that Americans fundamentally do not agree on whether guns are dangerous—or essential.

Todd worries that if more guns are removed from the hands of law-abiding citizens, a tyrannical government could take over—we could see an American Stalin or Mao. “More people would be murdered without the Second Amendment,” he said.

In the nearby town of Centennial, 64-year-old Carol Schuster said that’s one thing that keeps many conservatives from supporting gun control. “They’re afraid of the government,” she told me. She knows because she used to be one.

Schuster and her husband, Bill, own a company that sells big mobile filing cabinets, the kind that doctors use to store their patient records. Like many small-business owners, they long voted Republican.

The Schusters were terrified when Columbine happened, but they didn’t think it would keep happening. Those shooters were freaks, juvenile delinquents. “Another school shooting” hadn’t yet become a thing Americans say almost every month.

Carol Schuster outside her home in Centennial. (Kirsten Leah Bitzer)

Then came the Sandy Hook shooting, in which six- and seven-year-olds were mowed down as they cowered in their elementary-school bathroom. Schuster began to feel like her party wasn’t doing enough. (Just this week, Republican state legislators in Colorado rejected a ban on bump stocks, the devices used by the Las Vegas gunman that allowed his rifles to fire faster.) She attended a meeting of Colorado Ceasefire, a local gun-control group, and she was the only Republican there. “Oh,” she thought. “These Democrats really are nice people.” In 2016, Schuster voted for Hillary Clinton as a single-issue voter on guns.

Today, one portion of her office wall is devoted to photos of her family, another to pictures of dogs, and another to the front pages of newspapers covering all the mass shootings that have taken place since Columbine. “Important things,” she explained.

When she saw the Parkland shooting on TV, she decided she would go to Washington on Saturday to take part in the March for Our Lives. Her sign will read, “Former Republican for sensible gun laws.”

Schuster asked me where I was going next, and I told her I’d be interviewing Patrick Neville, a former Columbine student who survived the massacre and is now a Republican State Representative who supports concealed carry among teachers. Schuster said she had a lot of questions for him.

When I arrived at his office in the Capitol building in Denver, Neville looked red and tired. His press secretary seemed weary, too, from listening to dozens of voicemail messages, many of which wished to inform her that her boss was a “fucking asshole.” A bill Neville introduced, scheduled for a hearing just days after the Parkland shooting, called for allowing concealed-carry permit holders to bring their guns inside schools. “Get your head out of your ass!” one woman’s voice screamed on the answering machine. “Protect these children!” (Todd gets angry messages, too—including from people who tell him they wish he died at Columbine. The Schusters, meanwhile, say they get run off the road for their gun-control bumper stickers.)

Neville wasn’t inside Columbine when the shooting happened. He was just outside the building, skipping class to go smoke with friends. When he realized what was happening, he ran to a nearby house and called his mom. “I’m not going to be able to get to my next class,” he told her.

If Republicans are afraid of government overreach, then on the other side, “there’s an irrational fear of guns,” Neville said. Todd and Neville see guns as “tools” that can be safely used for fun or protection. Like Todd, Neville believes shooters target gun-free zones like schools because they know they won’t meet resistance. Not knowing which teacher might be armed is a “huge tactical advantage,” Neville argued. To protect his three young daughters, he plans to send them to a private high school, where teachers can carry guns.

This was the fourth time Neville sponsored the concealed-carry bill, and it failed like it always does, but he plans to introduce it again. Why? “Never a wrong time to do the right thing,” he said. The morning we spoke, another school shooting had taken place in Maryland.

Littleton, a Denver suburb, in many ways offers a typical middle-American landscape—dotted with drab office parks and Outback Steakhouses. Less typical are the striking, snow-streaked mountains, which loom in the background.

The light-beige Columbine High School building gets threats all the time. It’s the unholiest of holy sites: Several times a day, a security guard told me, random people stop by to take pictures or just to take a morbid look. The guard can’t allow them to do that; he can’t make the kids relive it that often.

Another security guard in the student parking lot kept a wary eye on me. But at 2:45, the glass doors swung open and perfectly normal students burst out of a perfectly normal school, laughing and asking each other about homework assignments. Among them was Kaylee Tyner, a junior who organized Columbine’s student walkout for gun control, which happened earlier this month.

Kaylee Tyner at her home in Littleton. (Kirsten Leah Bitzer)

The day I met up with Tyner, she had called a handful of her classmates to her house to make signs for Saturday’s march. Her friends plan to go to the local march in Denver, but Tyner will travel all the way to Washington with her mom. On top of her political advocacy, Tyner is in four AP classes, several clubs, and works as a waitress at a retirement home.

Tyner peeled a sticky note off the window of her Nissan—she’s in a club whose members leave encouraging messages for one another—and drove the four minutes from her school to her house. She put out some snacks and brought up tempera paints from the basement. The other girls trickled in a few minutes later. They huddled around Tyner’s dining-room table and laid out orange, black, and white poster boards. They’re Columbine’s core group of activists, and it’s something they’re surprisingly secure about. Once, a boy said something like “oh, there go the feminists” as they walked by, and one of them, 16-year-old Mikaela Lawrence, said simply, “Chh—yeah!”

The girls might get their news from social-media sites like Twitter, but, they tell me, they’re careful to check it against other sites to be sure it’s not “fake news.” Rachel Hill, a cheery 16-year-old, easily rattled off the gun measures she’d like to see: universal background checks, a ban on bump stocks, higher age limits and longer waiting periods. She painted a sign that read, “I have thought. I have prayed. Nothing changed.”

Kaylee and some friends work on signs for March for Our Lives at her home in Littleton, Colo.

The day after the Parkland shooting, the halls of Columbine were unusually quiet. Despite all the security, kids at Columbine periodically worry about another shooting happening there. Some of their teachers have panic attacks when the fire alarms go off, the girls said.

“We’re not gonna stop fighting until laws are passed,” said 14-year-old Annie Barrows, laying down her paint brush and hammering her fist into her hand. “There’s blood spilling on the floors of American classrooms.”

Kids who go to Columbine rarely joke about the shooting, but students from other schools sometimes make crass remarks, the girls said. “Going to Columbine, we don’t get to pick the label for our school,” Tyner said. “We’re one of the most infamous schools in America. We’re trying to show people that this affects your community for decades.”

One day in early April 1999, Daniel Mauser, a blond-haired, bespectacled Columbine sophomore, came home and asked his father, Tom Mauser, “Did you know there are loopholes in the Brady bill?”—the national law that requires background checks for gun purchasers. Tom didn’t think much of it. Daniel was on the debate team; he and his conservative classmate, Patrick Neville, would sometimes argue about politics.

Two weeks later, the day of the Columbine shooting, Tom didn’t know whether Daniel was alive or dead for nearly 24 hours. Late that night, authorities called to ask what Daniel had been wearing, or if the Mausers had any dental records. They said the Mausers would hear more in the morning. The following day at noon, the sheriff came along with some grief counselors to tell Tom that Daniel had been shot to death.

The Mausers stayed in the area, but they couldn’t bring themselves to send their surviving daughter to Columbine. Instead, she went to the nearby Arapahoe High School. It, too, had a shooting, after she graduated.

Tom, who worked for the state’s transportation department, took on a second role as a spokesperson for Colorado Ceasefire. He and his son shared a shoe size; he began wearing Daniel’s black-and-gray Vans to testify at hearings. In 2000, he successfully helped push through a measure to close the state’s gun-show loophole. He’s one of the few Columbine parents who speaks out about guns; some others support him but find it too painful to talk about, he says.

Over lunch at Panera Bread, he told me he doesn’t support arming teachers—there’s too much of a risk of crossfire, accidents, or police not knowing who the true “bad guy” is in a hectic shooting situation, he said. And what, are we going to hold first-grade teachers accountable for acting as soldiers would in combat? Many Republicans, he argued, seemingly “cannot acknowledge the danger caused by guns.” (Many Republicans, of course, argue Democrats can’t acknowledge the danger caused by restricting guns.)

One of the most helpful gun measures, he thinks, would be a state- or nation-wide red-flag law, allowing family members or law-enforcement officers to ask a judge to temporarily take away the guns of someone who seems dangerous.

At this point, a woman approached our table to thank Tom for his efforts. “You’re welcome,” he said.

The following day, Tom planned to go for a bike ride in the 70-degree weather, enjoy his retirement a little. But for the moment, he went back to talking about his dead son with yet another reporter. Because Columbine High has a stain, but so does the whole country, and it will endure until there aren’t any more stories like this left to tell. So he tells it.

Like Evan Todd, Daniel Mauser was in the library. Eric Harris insulted him, then fired his rifle and hit Daniel in the hand. Then the mild-mannered Daniel fought back—he pushed a chair at Harris. Harris responded by shooting him in the face.

I sat there speechless as Tom Mauser calmly ate a spoonful of soup. “This is America,” he said.

(Kirsten Leah Bitzer)