Columbine, Sandy Hook, Parkland.
These horrors left children and teachers killed in senseless school shootings.
Preventing another mass killing has become a critical part of safety plans at schools across the country.
For one local district there's a new way to keep kids and staff safe in the classroom.
It's an app called Share-9-1-1.
"It's an application that basically improves the communication if there's an emergency on campus," said Juliet Fine, the former principal at Horace Mann in Beverly Hills.
Fine showed the I-Team how the technology could work if there was an emergency. In a demonstration, a teacher in a classroom sees something suspicious, opens up the app and sends a message, setting off an alert.
"So with the situation that's happening, I know that it’s an active shooter alert. And so it’s from Dr. Bregy. He’s on campus. He saw a man with a gun entering campus off of Wilshire. The app instantly notifies local police, fire and all personnel at the school at the same time."
Fine said the school immediately goes into Active Shooter Mode. She said all the schools have these procedures already in place.
But this app allows her and others to continue posting and updating as the intruder moves about.
The updates go to everyone immediately, letting teachers and first responders know whether to keep students where they are, or get out.
"So if there was a shooter and they were shooting, we’d want to know is somebody injured? Where are they injured?" Fine said.
Michael Bregy, the Beverly Hills Unified School District Superintendent said if you look back at the history of some of the school shootings, things happen instantly, but the information seems to trail behind.
Bregy says the app lets people check in.
"Who is with them? Where are they? How close is the threat?" he said. "So police may be on their way, but they may be going to one place. It’s our staff now that become the ones to say 'hey, they were here, now I’m hearing this guy by my room.'"
In Parkland, Florida last year, officials blamed confusion about the location of the school shooter for causing delays in finding him.
The massacre took the lives of 17 people, a major reason Beverly Hills Unified decided to update its technology.
"I think it’s when you don’t have communication and don’t know what’s going on, that’s when you feel anxious and that’s when things lose control," Fine said.
The superintendent says the district will spend about $3 per student, per year on the new app. That’s a total of about $12,000 a year in Beverly Hills.