ALBANY, N.Y. (NEWS10) – A little more than three years ago the nation was struck by tragedy and we witnessed the horrific school shooting at Sandy Hook Elementary.

The tragedy inspired dozens of changes to security precautions at schools across the country. It even lead to a new business in Adams, Massachusetts that creates a unique glass to keep attackers out.

NEWS10 ABC’s Rachel Yonkunas explains how “school guard glass” works.

With this, you’re not buying glass – you’re buying time. The idea for school guard glass came the day of the Sandy Hook School Shooting in December 2012. The first police officer was on scene about three minutes after the 911 call. That gave a first grade teacher just enough time to hide her class and survive.

NEWS10 ABC sat down with that teacher, Kaitlin Roig-Debellis about that tragic day and her strong message to move forward. 

“My students and I were just in our morning meeting which is a very calm, quiet piece of our day, when very loud very rapid gunfire began over and over and over,” Kaitlin explained.

It was the morning of December 14, 2012 at Sandy Hook Elementary school. Former first grade teacher Kaitlin Roig-Debellis hid her 15 students as a shooter reloaded in the adjoining classroom.

“I said we need to get into our bathroom now. I picked some of my students up. Put them behind the toilet where the flusher is. Stood two of my little boys on top of the toilet, put my tiniest student on top of the toilet paper dispenser, holding her with my hand. I think back on it now and it seemed so impossible, but in that moment the impossible needed to become possible because that was our only chance,” Kaitlin said.

Kaitlin revealed the trauma of her darkest hour in her book choosing hope. It’s a story of surmounting tragedy. We asked her what was it like inside that bathroom, knowing what was going on.

“My students were in the middle of hell and what they were hearing was so loud and so scary that they understood that when I said ‘be quiet’. They understood that silence meant we might stay safe,” Kaitlin said.

The tragedy sent schools scrambling for security upgrades, but even the locks and cameras at Sandy Hook couldn’t keep the shooter out. 

“I am alive because I had the time to hide while he shot his way in.” Kaitlin said.

Now giving people time to stay alive is the mission at ‘School Guard Glass.’ Chris Kapiloff works in the glass-installation business in Adams, Massachusetts.

The day of the Sandy Hook shooting, he came up with the idea for school guard glass.

“The purpose of our glass is to keep somebody out of a building even if they come prepared to enter it with an assault rifle or a sledge hammer,” said Chris Kapiloff.

His neighbor, Co-President Foster Goodrich showed us how it looks and feels just like regular glass, but a laminate in the center, making it nearly unbreakable.

“Throw bricks at it, kick it, hammer, two by four, bat, three pound mallet, and then eventually to a sledge,” said Foster Goodrich.

And schools can afford it. 

The glass is five times cheaper than bulletproof products. Safe Guard Glass is $1300 per door and bulletproof glass is $6500 per door. It’s the cheapest door on the market so the makers were able to strengthen it and make it into a cohesive product that prevents forced entry. What they’re allowing is guys on the inside to engage in their protocol. And they’re also giving time for first responders to arrive.

That’s why it is going into the new Sandy Hook Elementary School. Which brings us back to Kailtin.

Weeks after the tragedy, she grappled to find answers that would never come.

“Why did this happen? Why our school? Why innocent lives? I decided I needed to shift my energy. Which lead me to create Classes 4 Classes.”

That’s a non-profit that gives students an opportunity to pay it forward to classrooms across the country.

“Everyone comes up against stuff in their lives that seem insurmountable and they absolutely do not have to be. And so if I can share that with one person by having them read choosing hope, then that’s exactly why I wrote it. There is light after darkness”

Classes 4 Classes is Kaitlin’s proof. The program matches classes in need with classes that have resources to spare. Then that classroom passes it on, so on and so forth.

School Guard Glass is being installed in at least eight schools across the country, but aside from Sandy Hook, we’ll never know which schools have it – simply for safety reasons.

Kapiloff says he doesn’t want anyone to know it’s there, unless it’s used to protect them.