Army and Homeland Security prepping teachers for the gunman at the door

The U.S. Army and the Department of Homeland Security have created a computer-based simulator that trains teachers on how best to react in an active-shooter situation.

The $5.6 million program – it's called the Enhanced Dynamic Geo-Social Environment, or EDGE – is similar to those used by the Army, in which a virtual environment helps train soldiers in combat tactics and scenarios.

The program is expanding to schools to allow teachers and other school personnel to train for active shooters alongside first responders. Homeland Security officials said the school version should be ready for launch by spring.

"With teachers, they did not self-select into a role where they expect to have bullets flying near them," said Tamara Griffith, a chief engineer for the project. "Unfortunately, it's becoming a reality. We want to teach teachers how to respond as first responders."

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Bob Walker, the project manager, said the program was designed to put a teacher in a situation similar to an active-shooter scenario.

Each teacher will get seven options on how to keep students safe, and some in the program might not respond or be too afraid to react. That, in itself, becomes another problem to be solved.

"Once you hear the children, the screaming, it makes it very, very real," Walker said.

The program can have the shooter be either an adult or a child.

"We have to worry about both children and adults being suspects," he said.

The designers of the program listened to real dispatch tapes from school shootings and talked to a mother of a child killed in the 2012 mass shooting at Sandy Hook Elementary School in Newtown, Connecticut. That shooting left 20 children and six educators dead after gunman Adam Lanza opened fire in the school.  

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"It gives you chills when you think about what's happening on those tapes," Griffith said. "It tore us apart to listen to her and what she went through."

The goal of EDGE was to serve one purpose: to train educators to save lives when an armed attacker busts through a school door, weapons at the ready.

School safety advocates say safety training gets pushed to the back burner until a tragedy happens. Amanda Klinger, director of operations for the nonprofit Educator's School Safety Network, said this new program could help change that.

"I hope that people will sort of see this simulation as a really cool and engaging way," she said, "to think about school safety."

John Verrico, a spokesman for the Department of Homeland Security told Fox News the program was free for administrators and teachers to download and the program was implemented partly due to concerns of active shooter situations at schools. 

"These active shooting scenarios are what we wanted to focus on first," Verrico told Fox News. 

Verrico could not elaborate if the program would be mandatory for educators but said it was a good way for teachers to train with police if these situations were to occur.  

Everytown reported there have been 271 school shootings in the U.S. since 2013.

The Associated Press contributed to this report.