Viral video shows how easy it is to overlook clues to a school shooting

There are few things we all dread seeing on the news more than the words: “School shooting.”

The images that come out of said incidents are horrifying and the school names quickly become synonyms of tragedy — Virginia Tech, Columbine, Sandy Hook.

Oftentimes after a shooting, people demand to know how the signs were overlooked. How could such a tragedy happen? Where were the teachers? The parents?

A new viral video produced by the parents of the victims of Sandy Hook shows how easy it is to miss the signs of a potential school shooting.

We’ll warn you now: This one gets uncomfortable at the end.