Pfc. Michael P. Giannattasio had been attending the Basic Reconnaissance Course at School of Infantry West, a physically demanding training course required for those who want to join the elite ranks of reconnaissance Marines.
He was discovered unconscious during a land navigation training event Aug. 30, according to a spokesman from Marine Corps Training and Education Command, Capt. Joshua Pena.
The San Diego Union-Tribune first reported Giannatasio's death.
Giannatasio, 22, was from Armada, Mich. According to a published obituary, he was the fourth of eight children.
He graduated from Notre Dame de la Salette High School in Olivet, Illinois, where he competed in cross country and rugby, becoming an all-state rugby player his senior year, according to the obituary.
Giannatasio then attended a year at Macomb Community College before enlisting in the Marine Corps Jan. 23, 2017.
According to the obituary, Giannatasio graduated from boot camp at Parris Island, South Carolina, on April 21, earning his recruit company's "Iron Man" prize by maxing out his physical fitness and combat fitness scores.
"The Marine Corps is in mourning and offer our deepest condolences," Pena said in a statement. "We continue to support the family during this difficult time. PFC Giannattasio was an outstanding Marine who stepped up to the difficult challenge of earning a spot amongst our distinguished reconnaissance forces."