Mourners across the country are remembering the students and teacher killed during a rampage by two Columbine students in Littleton, Colorado.
As Daniel Kemp tells us, the anniversary has schools and law enforcement reflecting on what's been learned from such a tragic day.
The first officers on that deadly scene had never trained for what they found at Columbine High School.
Now ten years later, the incident has transformed the way police and schools across the country deal with shooting rampages.
"We have heard shots and we know we have victims here," one reporter on the scene stated.
"I looked out the window and there's a kid with a trenchcoat and a shotgun throwing pipe bombs in the parking lot and then he shot a girl outside," another witness exclaimed.
April 20th, 1999.
Two classmates unleash one of the nation's deadliest attacks on a high school campus.
"After that incident, law enforcement nationwide took a whole new look at how to respond to a situation like that," explained Officer Barry Pruitt, with the Bowling Green Police Dept.
Today, police officers across Kentucky say they're taught how to neutralize the threat.
"Officers are now trained in active shooter scenarios. Whatever type of situation arises, our officers and trained on how to go in and deal with situations like that as quickly as possible," Pruitt said.
It's something that helps school officials.
"Just as we go through fire drills and earthquake drills, we also go through lockdown and lockout so students know what is expected," explained Joe Tinius, superintendent of Bowling Green Independent Schools.
Both Superintendent Tinius and Warren County Superintendent Dale Brown say security at all schools has been ramped up with software, visitor check-in's and secure entrances.
All efforts to keep students safe.
"You always hope something of that nature will not happen, but we have to be prepared," Tinius said.
Both superintendents say they work extensively with the police department on a regular basis discussing school safety.
Law enforcement also have detailed maps of every school, with a specific plan in place in the event a situation ever arises.