The Marines involved in an accident off the California coast last week that killed one and resulted in an unsuccessful search for seven others and a sailor were identified early Monday in a statement that said an investigation is underway.

All eight missing service members are presumed dead after a 40-hour search effort was unsuccessful. The mishap occurred Thursday off San Clemente Island at 5:45 p.m., where 15 Marines and one sailor were riding in an amphibious assault vehicle. Eight of the 16 service members were initially rescued while eight went missing.

Lance Cpl. Guillermo S. Perez, 20, of New Braunfels, Texas, was pronounced dead at the scene, the statement said. The statement said the presumed dead include, Pfc. Bryan J. Baltierra, 19, of Corona, Calif., a rifleman; Lance Cpl. Marco A. Barranco, 21, of Montebello, Calif., a rifleman; Pfc. Evan A. Bath, 19, of Oak Creek, Wis., a rifleman; U.S. Navy Hospitalman Christopher Gnem, 22, of Stockton, Calif., a hospital corpsman; Pfc. Jack Ryan Ostrovsky, 21, of Bend, Ore., a rifleman; Cpl. Wesley A. Rodd, 23, of Harris, Texas, a rifleman; Lance Cpl. Chase D. Sweetwood, 19, of Portland, Ore., a rifleman; Cpl. Cesar A. Villanueva, 21, of Riverside, Calif., a rifleman.

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Of the Marines rescued, one later died and two were hospitalized in critical condition, the statement said.

Fox News' Dom Calicchio contributed to this report