Search and rescue operations have been halted following a July 30 training accident off the coast of Southern California. Prior to the conclusion, authorities had been searching for seven Marines and a Navy sailor. At this time, they are all presumed dead and efforts have now turned to recovering the bodies.

The incident occurred during a 15th Marine Expeditionary Unit and Makin Island Amphibious Ready Group routine training exercise near San Clemente Island.

Around 5:45 p.m. local time, Marines in an amphibious assault vehicle (AAV) reported that they were taking on water. At that time, 16 members assigned to 15th MEU based out of Camp Pendleton had been inside the AAV. Following the accident, eight Marines had been pulled from the water, USA Today reports. One of the military members later died and two others currently remain hospitalized in critical condition, according to a statement from the Marines.

Throughout the search and rescue efforts, Marine Corps, Navy and Coast Guard helicopters and ships searched over 1,000 square nautical miles for more than 40 hours, but they eventually determined that a successful rescue was unlikely.

"It is with a heavy heart, that I decided to conclude the search and rescue effort," said Col. Christopher Bronzi, adding, "The steadfast dedication of the Marines, sailors and Coast Guardsmen to the persistent rescue effort was tremendous."

Continuing, he added, "Our thoughts and prayers have been, and will continue to be with our Marines' and sailor's families."

Marine Corps Commandant Gen. David Berger has ordered an immediate suspension of amphibious assault vehicles from training at sea.

At this time, circumstances surrounding the military training accident are being investigated.

US Marines
This representational photo reviewed by the U.S. military shows the United States Marine Corps emblem hanging on a wall at the Joint Detention Forces Headquarters at Guantanamo Bay U.S. Naval Base, Cuba, April 9, 2014. Getty Images/ MLADEN ANTONOV