Thursday, December 14, marks the five-year anniversary of a mass school shooting in United States’ Sandy Hook Elementary School. Adam Lanza, 20, shot and killed 20 first-graders and six staff members before ultimately killing himself.

Following the incident, two parents – Mark Barden and Nicole Hockley – who lost their children in the 2012 shooting started Sandy Hook Promise, a nonprofit organisation focused on preventing gun violence. On Monday, the group released a chilling public service announcement in the form of a faux news broadcast to stress that prevention of such shootings is indeed possible.

The supposed broadcast (video above) shows a “news reporter” at the scene of a school shooting, the day before it happens. She begins the broadcast saying, “I’m here at the scene of tomorrow’s shooting where a 15-year-old will kill four children, two adults and then turn the gun on himself.”

To showcase the complacency that has, so far, accompanied such shootings – “We never saw it coming” – and highlight the importance of reporting the warning signs, the “reporter” interviews students, a teacher, a mother and police officers to predict what they’ll say after the shooting is over.

The message: “You can stop tomorrow’s shootings if you recognise the warning signs today.”

Hockley told People Magazine, “(People) need to recognise the signs of violence now and say something before it’s too late, because once the act has taken place, it is too late to make a difference.”

Last year, Sandy Hook Promise released another poignant video (below) titled Evan.