The Air Force has opened its own investigation into how a lone airman could access and distribute possibly hundreds of highly classified documents, top Air Force leaders told Congress on Tuesday.

Air Force Secretary Frank Kendall said he has directed the Air Force inspector general to go look at the Air National Guard unit based in Cape Cod, Massachusetts, where Airman 1st Class Jack Teixeira served and “anything associated with this leak that could have gone wrong” and allowed the leak to happen.

Teixeira, 21, was charged Friday in the U.S. District Court in Boston with unauthorized removal and retention of classified and national defense information. He is expected back in court for a hearing Wednesday.

The leaks have raised questions as to how a single airman could have removed so many documents without being detected, why there were not safety checks in place and how the documents could have lingered online undetected for months.

“How could this guardsman take this information and distribute it electronically for weeks, if not months, and nobody knew about it?” Democratic Sen. Jon Tester of Montana asked the Air Force leaders testifying before a Senate defense appropriations subcommittee.

In addition, the Air Force is conducting a service-wide review of how each command handles classified information, Air Force Chief of Staff Gen. C.Q. Brown told committee members.

The Air Force’s own reviews are on top of a military-wide review directed on Monday by Defense Secretary Lloyd Austin. Austin has ordered that all military facilities that handle classified information report to him within 45 days on how they access, share, store and destroy the nation’s secrets following the leaks.

The leaked documents exposed to the world unvarnished secret assessments on the war in Ukraine, the capabilities and geopolitical interests of other nations and other national security issues.

Teixeira posted the highly classified material in a geopolitical chat room on Discord, a social media platform that started as a hangout for gamers.

“He had access to some aspects based on his job as a cyber administrator. He took advantage of that access,” Brown said.

(AP)