The U.S. Coast Guard announced Tuesday that the search for 12 marines who went missing after they crashed off the coast of Hawaii last week has been suspended after five days of searching, with the Marine Corps now turning their attention to "recovery and salvage efforts."

The suspension, which was effective immediately at sunset on Tuesday, comes after a five-day search that yielded no results beyond the discovery of four life rafts, reported ABC News. In total, rescuers searched more than 40,000 nautical square miles - about the size of Florida.

"A decision to suspend searching without finding survivors is extremely difficult given the depth of its impact. ... Our thoughts and prayers are with Marine Corps helicopter squadron and particularly with families and loved ones of those missing," Coast Guard Capt. Jim Jenkins said in a written statement.

The search for the 12 members aboard the two CH-53E helicopters began late Thursday when a civilian on a beach reported seeing the helicopters flying and then a fireball, while another reported seeing a flare, according to CNN. The U.S. Marine Corps notified the Coast that the men had gone missing, prompting a search that included the Navy, the National Guard, as well as Hawaii fire, police and Ocean Safety.

Breaking the story to the public, the Coast Guard initially reported that the helicopters had collided, but a later report from the U.S. Marine Corps said that it wasn't known whether there was a collision or not.

The missing crew members were identified over the weekend as:

- Maj. Shawn M. Campbell, 41, College Station, Texas.

- Capt. Brian T. Kennedy, 31, Philadelphia.

- Capt. Kevin T. Roche, 30, St. Louis.

- Capt. Steven R. Torbert, 29, Florence, Ala.

- Sgt. Dillon J. Semolina, 24, Chaska, Minn.

- Sgt. Adam C. Schoeller, 25, Gardners, Pa.

- Sgt. Jeffrey A. Sempler, 22, Woodruff, S.C.

- Sgt. William J. Turner, 25, Florala, Ala.

- Cpl. Matthew R. Drown, 23, Spring, Texas.

- Cpl. Thomas J. Jardas, 22, Fort Myers, Fla.

- Cpl. Christopher J. Orlando, 23, Hingham, Mass.

- Lance Cpl. Ty L. Hart, 21, Aumsville, Ore.

The cause of the crash is still under investigation, reported the Associated Press. Any further actions, including the recovery and salvage efforts, will be handled by the Marine Corps.