Altoona Area High School senior Kaylee Koller was only a second-grader when more than 1,500 miles away, two teenagers shot and killed a dozen of their classmates and a teacher, leaving the public to draw a collective breath of shock and horror.

Ten years ago today, Eric Harris, 18, and Dylan Klebold, 17, killed 13 people and themselves at Columbine High School in Littleton, Colo., in what is now known as simply Columbine.

"I remember my parents talking about [the events at Columbine], but I was too young to understand it," Koller said.

She is among a generation of students who don't remember when metal detectors and security cameras were just for airports.

Today, schools have emergency plans, organizations like Safe Schools advise parents on how to respond to a crisis and schools participate in drills with state police and emergency responders so everyone knows their role and place in case a real-life scenario unfolds.

Precautions are not without necessity.

According to the National School Safety Center's report on school-associated violent deaths, since the 1992-93 school year, 451 people have died from violence within and near schools.

The statistics include suicides and accidents on and near school grounds, and the information is gathered through newspaper reports.

Of the 451 deaths, 158 were for unknown reasons, 115 were for interpersonal disputes, 83 were suicides and 53 were gang related.

The report states 335 people were shot, while 64 were stabbed and 25 were beaten or kicked to death. The majority of victims, 350, were male.

California had the most deaths at 92. Pennsylvania totaled 28.

More than a decade before the shootings at Columbine rocked the world, AASD brought in security. Today, the force has eight full-time armed police officers.

Through the end of March, 19,280 people visited Altoona's high school, junior high and Stevens building, AASD Police Chief Jack Reilly said.

Arming the officers eight years ago was a direct result of Columbine, Reilly said.

District spokesman Tom Bradley said that before the Columbine shootings, schools were more relaxed about security.

Reilly said law enforcement has learned from Columbine how to respond to a school attack.

A school shooting closer to home took place Oct. 2, 2006, when Charles Carl Roberts IV, 32, shot and killed five school children and himself in an Amish schoolhouse in Nickel Mines, Pa.

State Trooper David McGarvey of the Hollidaysburg barracks said school emergency response drills became mandatory for the department after the Nickel Mines shootings.

The drills are held in the spring and fall and rotate throughout counties, he said. The drills hopefully will prevent a problem from escalating to the point of a Columbine or Nickel Mines situation, he said.

"The Columbine attack showed the weaknesses in school security," Spring Cove School District Superintendent Rodney Green said.

He said a mock drill was held at the district's middle school.

"You have to go through that level of readiness and simulation to fully appreciate what [you] have to have in place," he said.

Green said a concern for rural schools is their proximity to emergency responders. City schools are often closer to police stations and fire departments.

Koller said she doesn't worry about safety at AAHS.

"Nothing has ever happened to us before, and we have a lot of security to keep us safe," she said.

Students should feel safe, but complacency is one of his fears, Reilly said. He doesn't ever want to get too comfortable.

"It's part of the job now," Bradley said.

Mirror Staff Writer Amanda Clegg is at 949-7030. Katie Duffy is a senior at Altoona Area High School. She works at the Mirror through the School-to-Career program.