NEWTOWN, Conn. —- With terror in her voice, Barbara Halstead begged with police dispatchers for help, ending her 24-second 911 call with the haunting plea of “Sandy Hook School please” as 11 gunshots rang out in the background.

Those shots fired by Adam Lanza were in the hallway of the school on Dec. 14. Principal Dawn Hochsprung and school psychologist Mary Sherlach were the first of 26 victims, including 20 first-graders, killed in the rampage.

After months of debate, Newtown officials Wednesday released six 911 calls received by the Police Department as the shooting was unfolding. Halstead’s was the first made that morning. Custodian Rick Thorne could be heard on at least three.

The calls provide insight both into the terror faced by teachers and staff members and the poise with which they sought help in the face of immediate danger. The calls offer few new details on police response or Lanza’s actions that morning.

Thorne’s first call ended just as Lanza killed himself. His last ended with him urgently identifying himself to Newtown officers who entered the building nearly six minutes after they had arrived.

Another call came from a teacher who calmly described being holed up in her classroom with her students and how she needed to lock her door. While not identified on the tape, the details of the call match those discussed in some media outlets by first-grade teacher Kaitlin Roig. The description of the classroom location also matches Roig’s classroom.

In one call, an unidentified teacher who was shot in the foot tells the dispatcher that she is bleeding. She says there are children in the classroom with her, but the door is not locked and that she did not believe it was safe to lock it.

The 911 calls were released after a Superior Court judge denied an attempt by Danbury State’s Attorney Stephen Sedensky to keep them sealed. Town officials also sought to keep the calls from becoming public, saying they were concerned about how the release would affect victims’ families.

Lanza shot and killed his mother, Nancy, at their Newtown home before driving to the school, which he once attended. In a recently released report, Sedensky concluded Lanza acted alone in planning and carrying out the massacre. But an 11-month investigation could not determine a motive in the second-deadliest mass shooting in U.S. history.

Sedensky closed the investigation by announcing there would be no criminal charges filed in the case and releasing a report that portrayed Lanza as an isolated, socially inept 20-year-old with a fascination for mass killers that seems to have been developed as far back as the fifth grade.

Sedensky also released a detailed timeline of the events on the morning of Dec. 14 that shows Newtown police officers were outside the school for more than five minutes before entering. He concluded police believed there might have been more than one shooter and “acted accordingly.”