Just as the one-year anniversary of the massacre at Sandy Hook Elementary in Newtown, Connecticut, approaches, state police have released recordings of six desperate calls made to 911 as the shooting unfolded.

On Dec. 14, 2012, 20-year-old Adam Lanza opened fire on two classrooms in the school, killing 20 first-graders and six school employees before turning the gun on himself. Prior to the massacre, he killed his mother, Nancy, in their home.

Over the protestations of town and state officials, a request for the audio was granted by the Connecticut Freedom of Information Commission to the Associated Press. The court noted the calls would be “a searing reminder of the horror and pain of that awful day,” but would showcase the “bravery and professionalism” of first responders and serve to improve future law enforcement response in emergencies.

Families of those killed were divided by the tapes’ release, with some arguing it would cause more distress, and others lauding the added transparency.

Nicole Hockley, the mother of 6-year-old Dylan, said it would be difficult for families like hers and the community to hear. “I think as parents it’s just down to us to ensure our children and families are protected from hearing those for as long as possible,” she told MSNBC. Gilles Rousseau, father of substitute teacher Lauren, was in favor of the release. “I think the more the public knows, there will be less confusion, there will be less people making stories about what happened,” he told Today.

Below are audio files of some of the 911 calls. Warning: the calls can be difficult to listen to.

The First Call

The first sign that something was awry at Sandy Hook Elementary came from the school’s secretary, Barbara Halstead. “I think there’s somebody shooting in here,” Halstead tells the 911 dispatcher in a 24-second call. When asked why she thinks that, she replies she just caught a glimpse of someone running down the hallway with a gun.

‘There’s Still Shooting’

“I believe there’s shooting at the front glass, something’s going on,” head custodian Rick Thorne tells a dispatcher in another call, who instructs him to take cover and conveys an order to fellow 911 dispatchers to “get everyone you can going down there.”

“I keep hearing popping,” Thorne says, and after three minutes on the line, as gunshots pop in the background, pleads, “There’s still shooting going on, please.”

A Teacher Is Told to Shelter Students

“It sounds like there are gunshots in the hallway,” a teacher tells the dispatcher, who instructs her to lock the door of her classroom, keep the students calm, and stay away from the windows.

Shooting Victim Dials Police

A woman shot in the foot spoke with state and local authorities from Room 1 inside Sandy Hook. "Are you safe now?" the dispatcher asked. "My classroom door is not locked...there's children in this room," she replied. Messages from inside were spreading through the town, and shortly after, a woman calling said a friend had texted her from inside the school. As dispatchers calmly coordinated response, phones rang in the background and calls went out to state police.