It looks a lot like any other high school: blue lockers, fluorescent overhead lights, kids carrying musical instruments and gym bags.
But Columbine High School's history as a site of a deadly school shooting sets it apart. Some of the changes are physical — the building has a new library to replace the old one, where a majority of the students were killed that day. Now, a plaque is mounted at the library's entrance, dedicated to the 13 victims.
Other changes are more systemic. This school shooting changed the trajectory of mental health services in Colorado schools, with the goal of preventing future violence. Over the years, it has continued to shape the national conversation, as well.
Finding 'A Place Of Community And Love'
Noel Sudano is a guidance counselor at Columbine. She smiles and laughs often, despite the difficult issues she deals with routinely.
"Anxiety is huge and there are a lot of kids that are dealing with higher levels of anxiety then I ever remembered coming up in high school," said Sudano.
A recent study by the Pew Research Center confirms what Sudano is seeing: high levels of depression and anxiety reported by teens. She also deals with issues related to suicide, which is a growing problem in Colorado.
As for school shootings, Sudano says that some kids do worry but that she doesn't see much of a connection between the shooting 20 years ago and concerns today.
"So for me personally, I don't really bring it up unless I am having a really heavy conversation with a kid that's talking about grief and loss," Sudano explains.
Sudano is not only the school's guidance counselor, she was also a Columbine student in 1999, one of a handful of former students who now work there.
Sudano was a sophomore in 1999.
"(W)hen everything started happening, I was in my math class," she said. "I remember that day it turned from, like, flirting screams to, like, terrified screams. And my teacher, she tried to kind of keep lecturing through it and then she stopped and I could see her face just went white."
Sudano made it out of the school.
"It was just hundreds of kids just pouring out of the building, running down that hallway and out the side door," she remembered.
Teachers told students to run and hide in a nearby neighborhood.
"So I went with a group of probably about 30, maybe 40, kids," said Sudano. "We ran to another student's house and kids were like scattered throughout the neighborhood."
Eventually they got word to go to Leawood Elementary School, where Sudano's son goes now.
"You couldn't leave unless a parent came to pick you up. I had never seen my dad look so shaken," said Sudano. "He hugged me so tight."
Sudano said she initially struggled to believe there were shooters in her school:
"I remember someone said to me, 'There are kids in our school with guns.' And I refused to believe it until I saw something on the news. It just seemed so completely impossible that I think that's a representation of the general thinking at that time."
So why, after that experience, did Sudano return to Columbine as a professional?
"It's weird, right?" Sudano said, with a laugh. "I think that it just felt like a calling to me. It felt like an opportunity for me to serve the community that did so much to wrap its arms around us on such a horrible day."
She says coming back has also helped her process what she went through.
"It helps me to reclaim some of the emotions that I have towards Columbine," she said, "because now, I can say that this is a place of community and love and health and joy. And when I finished high school, it didn't necessarily feel that way."
Mental Health Care Since Columbine
A task force put together by Colorado's governor in 2000 recommended all sorts of measures, including anonymous tip lines, bullying prevention programs and threat assessment teams. A lot of it has been put in place in the years since.
States, school districts and communities around the country are making their own changes. Last year, Virginia and New York became the first two states to pass laws requiring mental health education in schools. A new wellness center recently opened in Parkland, Florida, to serve students, parents, and faculty after the nearby school shooting at Marjory Stoneman Douglas High School last year, and in March, a pair of apparent suicides.
"I do think that there's a lot more conversation about things to look for and red flags," Sudano said. "Unfortunately I think a lot of those things have been learned from what happened at Columbine."
Sarah Goodrum is the chair of Criminology and Criminal Justice at the University of Northern Colorado. She recently testified at the state Legislature about what Colorado has learned on school safety over the last twenty years.
"I think for a while there was the perception that schools are built to provide education," said Goodrum. "That they're not built to provide mental health or social support services. I think that philosophy has changed a lot since Columbine."
She explains why mental health services are an important part of violence prevention with an iceberg metaphor. The kids who become school shooters represent the tip of the iceberg, the worst-case scenario.
"We want to work on moving our efforts more toward prevention so that we can get at the underlying root causes of violence," said Goodrum, "not just the worst-case scenario of school violence."
The types of incidents and struggles that are much, much more common than shootings are the rest of the iceberg. Things like "bullying, physical fights, suicidal ideation, self harm. We know that there's pain," said Goodrum.
She emphasizes that there is a lot more work to do on this issue.
But what Goodrum's iceberg metaphor also shows is that some of the programs put in place after Columbine have gone beyond stopping the next school shooter and have ended up impacting, and in many cases helping, all sorts of kids.
For example, Safe2Tell is a phone number, website and app launched after the Columbine shooting where anyone can anonymously report a concern or threat. Wyoming has since adopted it and similar programs are in place in several states, including Pennsylvania, Maryland and Nevada.
Guy Grace, the director of security at Littleton Public Schools, is one of the people who actually fields Safe2Tell messages. He gets the alerts throughout the school day, in the middle of the night, on weekends and holidays.
"A lot of time Safe2Tells come about 6 o'clock and I'll be at the gym and I'll be on their elliptical trainer at the weight room," Grace said.
Grace then sends the alerts to the appropriate people, such as law enforcement and the district's mental health workers. During the 2017-2018 school year, 16,000 tips came in statewide through Safe2Tell. The most common are suicide threats, followed by drugs and bullying. Over the course of that school year, 692 Safe2Tell messages were classified as "Planned School Attack," according to Safe2Tell documentation.
Unfortunately, the system doesn't always work. Grace described receiving Safe2Tell reports of suicidal kids but then not getting there in time.
Grace says he's still willing to devote his free time to Safe2Tell, "because it works."
Littleton Public Schools also have some serious physical security: Over 100 video screens, over 1,000 security cameras, audio feeds and an automatic background check system to screen for sex offenders. Grace says he relies on technology as his "last resort."
"So when I look about mental health, it's wonderful to see now that we are trying to get on that to where we're trying to stop a school shooting, or a suicide, or bullying or whatever that hazard is related to mental health before it blows up into something bigger," Grace said.
Grace, the director of security at Littleton Public Schools, and Sudano, the guidance counselor at Columbine High School, have two very different jobs on paper, but come to pretty similar conclusions on mental health care in schools.
"I think this year in particular, in my own grief process of still processing what happened on April 20, (1999), I think I'm feeling more of a calling to really be mindful of this mental health problem," Sudano said. "I guess I'm like an eternal optimist. I want to think that there's something we can do that's preventative. That we can always find this path of redemption or positivity or growth. I guess contributions that each of these kids can make to our community and our society."
In 1999, the nation was shocked by a school shooting at Columbine High School. Columbine Then & Now explores what's changed and what has stayed the same over the past two decades.
Lisa Dunn contributed to this reporting.
Guns & America is a public media reporting project on the role of guns in American life.