As America emerged from the pandemic, communities continued to experience a rising tide of gun violence. School shootings and the rate of children and teens killed by gunfire both reached all-time highs since at least 1999. ProPublica’s coverage of gun violence reveals how first responders, policymakers and those directly affected are coping with the bloodshed.

This article is produced in collaboration with The Texas Tribune and the PBS series FRONTLINE. Sign up for newsletters from The Texas Tribune and from FRONTLINE.

“Inside the Uvalde Response,” a documentary that is part of the collaboration, premieres Tuesday at 10 p.m. EST on PBS stations (check local listings) and will be available to stream on the PBS App, YouTube and FRONTLINE’s website.

The May 2022 gun massacre at Robb Elementary School in Uvalde, Texas, left 19 children and two teachers dead. It was one of the deadliest school shootings in U.S. history.

More than a year and a half later, findings from a state-led investigation into the chaotic response — in which officers took more than an hour to take down the shooter — have yet to be released. Most of the officers involved in the response have declined to talk publicly about what happened that day.

But FRONTLINE, The Texas Tribune and ProPublica gained access to a trove of the materials from the investigation and were able to review the accounts of almost 150 responding officers, as well as hours of body camera footage and 911 calls.

In a new documentary, “Inside the Uvalde Response,” and article that publish Tuesday, the news organizations draw on these materials to reconstruct the day’s events, giving a detailed analysis of one of the most criticized mass shooting responses in recent history, and providing extraordinary real-time insight into law enforcement’s thoughts and actions. The film features never-before-published interviews conducted by state and federal investigators in the days immediately after the shooting.

Accounts in the documentary suggest that officers didn’t initially realize there were children in the school’s classrooms, as the kids were doing what they’d been taught to do in active shooter trainings: remain out of sight and stay quiet. An effective chain of command was absent. And failures in communication throughout all levels of law enforcement compounded the confusion.

“Inside the Uvalde Response” premieres Tuesday at 7 p.m. EST at and on the PBS app, and at 10 p.m. Eastern/9 p.m. Central that night on PBS and FRONTLINE’s YouTube channel.