"It sounds like there are gunshots in the hallway," the unidentified teacher can be heard telling a dispatcher during a 24-minute call from a classroom at Sandy Hook Elementary in Newtown, Conn., where she was holed up with her students. "The door isn't locked. I have to go lock the door."
Another of the many callers, the New York Times reported, was a custodian who stayed on the line with police nearly throughout the Dec. 14, 2012, shooting spree in which 26 students and staff were killed.
"I keep hearing shooting," he said. "I keep hearing popping."
The gunman Adam Lanza, 20, who also killed his mother before heading to the school, concluded the rampage by killing himself.
New Britain Superior Court Judge Eliot D. Prescott allowed the recordings to be released, upholding a ruling by the Connecticut Freedom of Information Commission, over the objections of Danbury State's Attorney Stephen J. Sedensky III.
Prescott noted the calls were "harrowing and disturbing," but that no children were identified by name and no caller indicated seeing a child being hurt.