A tragedy has befallen the U.S. special operations community as a Special Forces staff sergeant died in a drowning accident on Tuesday. The drowning occurred during a training event of the intense Combat Diver Qualification Course (CDQC).

“The Staff Sergeant was a student in the Special Forces Combat Diver Qualification Course, and was participating in a conditioning exercise in the pool, which stresses the students’ cardio, respiratory and muscular endurance,” according to a press release from the Army Combat Readiness Center and the John F. Kennedy Special Warfare Center and School (SWCS) cited by Military Times.

According to the press release, the staff sergeant belonged to the 10th Special Forces Group.

The death happened at the Army’s Special Forces Underwater Operations School, in Key West, Florida.

“During the training event, the Soldier submerged and did not resurface. The cadre immediately entered the pool and found him unresponsive,” the SWCS’s statement added. “The Dive Medical Officer attempted to resuscitate him, and he was transported to the Lower Keys Medical Center Emergency Room where he was pronounced dead following full medical intervention.”

One of the Most Demanding Courses in the Army

Special Forces Soldier Drowns During Combat Diver Training
Students prepare to depart for Fleming Bay for the 1,500-meter swim during the Combat Diver Qualification Course at the Special Forces Underwater Operations School in Key West, March 10, 2010. The school is part of the U.S. Army John F. Kennedy Special Warfare Center and School located at Fort Bragg, NC. (Photo by Major Dave Butler/SWCS)

The Special Forces Combat Diver Qualification Course is one of the most demanding and grueling courses in the Army. It lasts six weeks and trains Special Forces students in waterborne operations. Some of its graduates cite it as the hardest course they have attended. As a result, CDQC enforces “stringent safety protocols.” Unfortunately, this did not prevent the staff sergeant’s death.

The Combat Readiness Center (CRC) has started an investigation into the drowning, according to CRC’s spokesman Michael Negard.

As per standard policy, the identity of the Special Forces staff sergeant has not yet been released.