Seaman James Derek Lovelace, 21, of Crestview, Fla., died during Basic Underwater Demolition/SEAL (BUD/S) training in Coronado, Calif., Friday. (U.S. Navy photo)

The Navy is investigating the death of a U.S. sailor who lost consciousness during initial Navy SEAL training, the service announced Tuesday.

Seaman James Derek Lovelace, 21, of Crestview, Fla., died during the legendarily difficult Basic Underwater Demolition/SEAL (BUD/S) course at Naval Amphibious Base Coronado in California. Navy officials said in a news release that Lovelace was helped to the edge of the pool by instructors after having undisclosed difficulty on Friday. Efforts to revive Lovelace were unsuccessful, and he was pronounced dead at a nearby hospital, Navy officials said.

The news of the sailor’s death was first reported by the Virginian Pilot.

Lovelace was in the first week of SEAL training and performing an exercise that assesses and tests the ability of students in water. The exercise includes treading water and swimming while wearing diving masks and a camouflage utility uniform, according to the Navy.

Lovelace attended high school at Crestview High School on the Florida Panhandle, where he was varsity baseball team captain, according to biographical information released by the Navy. He studied mechanical engineering at Faulkner State Community College in Alabama before enlisting in the Navy in November.

An obituary published online for Lovelace states that he is survived by his father, two sisters and numerous other family members. He graduated from the Navy’s boot camp in Great Lakes, Ill., in January.

Adam Goldman contributed to this report.