As students around the state return to school for in-person learning, Sandy Hook Promise is telling teachers and students how they can prevent gun violence before it starts.

The group’s co-founder Mark Barden lost his 7-year-old son, Daniel, in the 2012 shooting at Sandy Hook Elementary.

"We are training students across the country how to know the signs and how to connect with their peers, and how to even self-report, if necessary,” he says. "Yesterday should have been [Daniel’s] first day as a sophomore at Newtown High School.”

Barden says the organization’s anonymous tip line has been busy all year, and calls are now skyrocketing as school gets back into session. He says feelings of isolation and depression are common in teens, and the pandemic and quarantine have only made things worse.

"Some people feel like they're invisible. And it's an awful feeling and if that goes on for a long time, it can lead to other things,” says Barden.

He says breaking through that isolation can help stop violence before it starts.

"Just start with ‘Hello’ and make that person feel validated, and that they've been noticed, and they do exist,” he says.

Sandy Hook Promise says there are often warning signs before a school tragedy and their mission is to train teachers and students to recognize them and seek help. It plans to debut its next set of PSAs in September.