A Marine died during a nighttime live-fire exercise at Camp Pendleton, California, on Thursday, the service said in a statement.
The Marine, who was a student at the School of Infantry-West, was not named in the statement because, according to a Marine Corps spokesman, their next of kin were only notified Friday morning.
"An investigation into the circumstances of the death is ongoing and the command is fully cooperating with the investigation efforts," the statement added.
The statement did not specify whether the death was firearm related.
The School of Infantry is the second stop for every Marine following graduation from basic training. The school is geared at training Marines on common combat skills and basic infantry tactics before many go on to receive their job-specific training.
The Marine Corps has two infantry schools -- School of Infantry-West at Camp Pendleton and School of Infantry-East at Camp Lejeune in North Carolina.
The Marine Corps has had some issues with recruits dying during basic training over the last several years. Five Marine recruits have died at Parris Island in South Carolina in the last two years.
The death of one of those recruits -- Dalton Beals in 2021 -- led to a charge of negligent homicide against one of his drill instructors. A military jury found him not guilty in July.
The Marine Corps statement said that the school "is providing support to the family and peers of the deceased during this difficult time."
-- Drew Lawrence contributed to this report
-- Konstantin Toropin can be reached at firstname.lastname@example.org. Follow him on Twitter @ktoropin.