Why US parents are placing door stops inside their children's school bags.

As the United States grapples with the scourge of gun violence continuing to afflict schools, and the nation’s lawmakers remain unwavering on the nation’s pro-guns stance, parents are trying to find ways to protect their children.

And one woman’s simple piece of advice involving a door stop has reverberated around the world.

Katie Cornelis described on Facebook how after the Sandy Hook primary school shooting in 2012, she gave her two nieces a small rubber door stop to always keep inside their backpacks. The idea behind it is that should a school shooting happen, and the classroom door swings inwards, the door stop can be used to keep the gunman out.

“It truly pained me when I handed it to them, and I didn’t want to scare them, but it was out of love and they understood,” Cornelis wrote, alongside an image of a door stop in her hand.

"Sure it’s small, but it can be powerful in keeping you safe if you ever have to barricade yourself in a room. If a gunman shoots out the door lock it will still keep the door from opening and may just buy you some time."

The Conneticut said she was "really sad" to post her tip, but she felt compelled to share it as she received it from a "security expert" and she wanted to pass it along.

"I pray no one ever has to use it," she wrote.

Cornelis' post was originally written in mid-February in the wake of the Parkland shooting in Florida, which left 14 students and three staff dead. But her words have since resurfaced, and they have been shared by more than 1.4 million people on Facebook.

Some parents immediately took on the advice and commented with thanks. Others hoped a scheme could be set up so each classroom had at least one door stop.

"This is such a powerful and important idea and message," one wrote.

"Unfortunately this is the world we are living in but it doesn’t hurt to try to be as safe as possible," said another.

One woman raised that it was a good opportunity for parents to speak to their children about safety and "being aware of where there are doors in their schools that do close the way this would be effective to close anyone out".

"This is also helpful to keep doors open. A few people died in the recent tragedy because they were holding doors open for people to flee. Which is terrible to have to speak with your children about such scary preventative measures, but these children are already scared seeing this stuff all over the news," she added.

Overwhelmed by the response to her post, Cornelis said she was "on a mission now to get this message to schools across America so each classroom will have one and every child will have one in their backpacks".

One teenager had similar thinking to Cornelis when he invented a device he named 'JustinKase' which essentially acts as an enormous and much firmer door stop. It's since been bought by several US schools.

Of course, little children should never have to think about gun deaths, and a door stop is not going to put an end to gun violence. But in 2018 alone, there have been at least 53 incidents of gunfire on school grounds, according to Everytown statistics. It's a staggering number to wrap your head around.

So while anti-gun advocates continue their fight to change legislation, if a parent's small act of placing a door stop inside a school bag can save at least one child, this provides some comfort.