A gun safety advocacy group formed after the 2012 mass shooting at Sandy Hook Elementary School released a provocative commercial Wednesday highlighting the threat of gun violence in schools.

The ad , from the group Sandy Hook Promise, begins like other back-to-school commercials, with children touting their new school supplies over light and cheery music.

"This year, my mom got me the perfect bag for back to school," a boy says at his locker. Another student says her binders help her stay organized and another talks about how his new headphones help him study.

The ad darkens as a young boy runs through the halls, exclaiming that his "sneakers were just what I needed for the new year" while screams and gunshots are heard in the background.

"My parents got me the skateboard I wanted. It's pretty cool," a student says as he uses it to break a window in order to escape a shooter.

Another student claims her new socks "can be a real lifesaver" while she uses one as a tourniquet on an injured student's leg.

The final scene is of a girl hiding in the bathroom while she texts her mom that she loves her with the phone she finally got "to stay in touch with my mom."

"It's back to school time, and you know what that means," the commercial continues. "School shootings are preventable when you know the signs."

After the ad aired, several Democratic presidential candidates tweeted it with messages of support.

Beto O'Rourke, who said his administration would confiscate assault weapons , tweeted that kids shouldn't "have to wonder if they're going to make it home. We need to buy back all of these assault weapons."

Andrew Yang tweeted that "Common sense gun laws can help fix this problem. We can't let this become the new normal for our children."