Image copyright Sandy Hook Promise

The families of children killed in the Sandy Hook mass shooting have put out a haunting video, showing how "back to school essentials" can be used to survive a school shooting.

It starts out normally enough, with kids showing off their new bags and snazzy folders.

The mood shifts, when one boy puts on his headphones and fails to see people behind him running from gunshots.

It ends saying "school shootings are preventable if you know the signs".

The video has been published by Sandy Hook Promise, a non-profit organisation led by the families of children killed at the Sandy Hook primary school in Connecticut in 2012.

Media playback is unsupported on your device Media caption The haunting video shows how "back to school essentials" can be used to survive a school shooting

On 14 December 2012, 20 children - aged between five and 10 - and six staff members were killed at Sandy Hook when a gunman opened fire with a semi-automatic rifle before killing himself.

The video changes suddenly from smiling kids showing off their new trainers and skateboards at the start of the new school year, to them using those same items to escape gun violence.

"We don't want people to turn away from it, so pretending it doesn't exist is not helping to solve it," said Nicole Hockley, whose six-year-old son Dylan was killed at Sandy Hook.

"At the end, the girl with the phone gets me every time," she told NBC.

Media playback is unsupported on your device Media caption Roman's best friend was among 22 people killed in El Paso in August 2019

This year, by 19 September - the 263rd day of the year - there had been 302 mass shootings in the US, according to the Gun Violence Archive.

If the current trend continues, 2019 is set to be the first year since 2016 with an average of more than one mass shooting a day.

In response to two mass shootings in August, US President Donald Trump said "serious discussions" were taking place about introducing "meaningful" background checks for people who want to buy guns.

To protect against potential violence, one US school is being rebuilt with concrete barriers in hallways so students can hide from bullets.

Mark Barden, co-founder of Sandy Hook Promise, says he refuses to accept school shootings as "our new normal".

"This is what our kids are having to think about now, and they shouldn't be. There is nothing normal about kids being shot, being hunted in their school."

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