In the latest sign of these AI-heavy times, the National Transportation Safety Board temporarily removed access to its docket system after discovering that voices of pilots who were killed in a UPS plane crash last year had been re-created using AI and were circulating on the internet.

The NTSB is prohibited by federal law from including cockpit audio recordings in its docket system, which otherwise contains troves of data on investigations and has historically been open to the public. But the accident docket for this flight included a spectrogram file of the voice recorder. A spectrogram uses a mathematical process to turn sound signals, including low and high frequencies, into an image.

Scott Manley, a popular YouTuber whose channel combines physics, astronomy, and video games, noted on X that it could be possible to reconstruct audio from the megabytes of data encoded in that image.

And that’s what happened. People took the spectrogram, along with the publicly available transcript, to create approximations of the cockpit voice recorder audio from UPS Flight 2976 in Louisville, Kentucky, according to the NTSB. They used AI tools like Codex, according to posts on social media.

The agency restored public access to the docket system on Friday but kept 42 investigations closed pending review — including the one related to Flight 2976.