WASHINGTON, May 25, 2023 (BSS/AFP) - A US Navy investigation released Thursday identified major concerns with the brutally difficult training that produces members of the elite SEALs special forces.

The probe -- which was launched following the February 2022 death of Seaman Kyle Mullen during training -- found "failures across multiple systems that led to a number of candidates being at a high risk of serious injury."

It highlighted problems including insufficient oversight by leadership, lack of risk assessment, a medical system "not trained, organized, integrated, or drilled to ensure continuous effective medical monitoring or care," and performance-enhancing drug use.

Mullen died of what was ultimately diagnosed as pneumonia just after completing "Hell Week" -- during which candidates are pushed to their physical limits while being deprived of sleep -- while other members of his training class were hospitalized, the investigation found.

He and other class members received medical care for respiratory issues during "Hell Week," but that information was not provided to the clinic that conducted the final medical check following its conclusion, and it cleared him to rest in the barracks.

In the barracks, he was monitored by "junior watchstanders with no medical or emergency care training" -- one of whom who did however call a duty medical officer as Mullen's condition worsened.

The medical officer said the seaman could go to the hospital if he was in "bad shape" but that all candidates would be evaluated in the morning, and Mullen repeatedly declined to do so.

Mullen only received medical treatment after a class officer later called 911 when told by the watchstanders that the seaman's condition was declining.

The Navy SEALs have carried out some of America's most dangerous and storied raids, including the May 2011 killing of Al-Qaeda leader Osama bin Laden in Pakistan.

SEAL is an acronym for Sea, Air, Land, reflecting their specialized capabilities.