IT’s the scene of nightmares.

Repetitive ones.

The boots of a gunman echoing down a school hallway. The crash of doors being forced open.

Gunfire.

There’s a seemingly endless spate of school massacres in the United States.

Students there have become so terrified at the prospect they will become the next trapped victims that they’re endeavouring to find solutions themselves.

A Connecticut woman has posted on social media about how her nieces are now carrying rubber door stops in their backpack. If there is a shooting, they want to wedge them beneath their classroom’s doors.

“If a gunman shoots out the door lock it will still keep the door from opening and may just buy you some time,” she wrote on Facebook.

After all, the gunman is after quick, easy targets.

The idea has been shared some 1.4 million times.

The strength of school doors has emerged as a central issue in students’ minds.

It’s a scene reinforced last week by reports of the heroism of 15-year-old student Anthony Borges. He was shot five times while using his body to brace a Marory Stoneman Doughlas High School door closed in an effort to protect his classmates.

But students themselves have been working on ideas to prevent such self sacrifice being needed again.

One such example has emerged in Wisconsin.

JUSTINKASE

Somerset High School student Justin Rivard had read the same disturbing story time and again.

Students had simply been unable to lock themselves safely away from attackers.

The basic latches on their classroom doors were not strong enough to resist a determined hip-and-shoulder, or a well-placed bullet.

So he took his creativity to his steelworking class.

There he devised an interlocking device of steel plates and connecting rods. His idea was to brace it beneath a door and its supporting posts.

He then put it to the test the best way he knew how: he recruited his school’s hefty American football linemen to try and bust it down.

They failed.

“You can lock a door with a lock, it can get shot out,” Justin says. “You can lock a door with this, it can’t get shot out. You can’t get around it.”

He has filed for a patent on his design.

He’s dubbed it the “JustinKase”.

And he’s offered his handmade product for sale: at $US95 (A$121) each.

SELF DEFENCE

According to local media reports, Justin’s school immediately ordered 50 of them — one for each classroom.

School principal Shannon Donnelly quickly made sure everyone knew how to use them.

“We immediately, within a week of having these, went through an entire drill, all throughout the building, really walking through students and staff,” she says.

But the principal was determined to take the safety measure further — to the whole school district, in fact.

“We started with the high school, then went to the middle school, then the elementary school,” Shannon Donnelly says.

He’s not the only student to identify the problem and come up with a solution.

A group of students at Benjamin Banneker High School in Washington DC are working on a device that can be quickly used to brace the hydraulic soft-door closing arms fitted to most school doors.

They’ve been awarded a $US10,000 grant to develop the concept, and a group of lawyers have offered free assistance in filing for a patent.