A U.S. sailor died Friday during a SEAL training exercise in Coronado, California, officials confirmed.
Seaman James Derek Lovelace, 21, passed out in a military training pool while undergoing basic underwater demolition/SEAL training (BUD/S), officials said.
Lovelace was withdrawn from the exercise when he began to have difficulty with the drill, Navy officials told NBC News. The sailor lost consciousness and efforts to revive him were unsuccessful.
Lovelace enlisted in the Navy boot camp in November and started prep training for BUD/S in January, according to Lt. Trevor Davids, spokesperson for Naval Special Warfare Center.
"Our heartfelt condolences go out to the family and friends of Seaman Lovelace. Though Derek was very new to our community, he selflessly answered his nation's call to defend freedom and protect this country. He will be sorely missed. We share his family's grief in this grave loss," said Capt. Jay Hennessey, commanding officer of the Navy Special Warfare Center, in a statement to NBC 7 San Diego.
The Navy had not announced the training death until after officials were contacted Tuesday by NBC News and The Virginian-Pilot newspaper in Norfolk.
The death is now under investigation, according to the report.
BUD/S is the SEAL's infamous training course with several phases, including one called "Hell Week." The majority of trainees who enter the program end up ringing the bell to quit. The small percentage that complete the entire program earn the SEAL trident on their uniform.
Friday's incident happened during the first week of BUD/S as trainees are being introduced to the water training, Davids said. It involves swimming in a pool, treading water as well as wearing dive masks.
No other information was immediately available.
Check back for updates on this developing news story.