A salvage crew worked into the night Friday trying to recover the fuselage of a Louisiana National Guard Black Hawk helicopter that crashed off the coast of Florida on Tuesday during a training exercise with four state guardsmen and seven Marines aboard.

The Marine Corps released the names of its service members Friday, though the National Guard has not identified the four guardsmen involved in the crash. The Guard has said the bodies of two soldiers have been recovered, but they believed the other two still missing are located within the wrecked and sunken helicopter. They are withholding identities of all the guardsmen until they recover the bodies of the final two, Col. Pete Schneider said Friday.

Recovery efforts of the craft were anticipated to last into the night, and military authorities expect the search will conclude Saturday afternoon after divers return to the crash site for a last mission to look for the bodies of the two guardsmen and debris, said Eglin Air Force Base spokesman Andy Bourland.

The civilian salvage crew from Mobile, Alabama, was summoned Thursday, but storms have caused delays.

“Weather’s been slowing everything down,” said U.S. Coast Guard Lt. Lily Zepeda.

Once brought up, the helicopter wreckage will be transported to Hurlburt Field near Eglin, where the craft launched before the crash. Once at Hurlburt, the craft will be turned over to a nine-member military investigation team, which arrived in Florida on Wednesday afternoon.

The Centralized Accident Investigation Team is composed of members of the Army, Navy and Army National Guard with expertise in aviation, said spokesman Michael Negard, of the U.S. Army Combat Readiness Center at Fort Rucker, Alabama.

“They look at it from a couple of different perspectives,” Negard said.

The military will consider three broad components that may have contributed to the wreck. The team will determine whether environmental factors such as weather, material failures such as equipment malfunction, or human error caused the wreck. Negard said it is too early in the investigation to speculate on a specific cause for the crash.

Investigators likely will interview staff at Eglin, any witnesses to the crash and the crew of the other Black Hawk that launched with the crashed helicopter but safely returned to base.

They also will examine the wreckage itself. The National Guard has confirmed that the helicopter had a flight recorder on board.

The operator’s manual for the Black Hawk describes the black box as “a crash-survivable digital tape recorder providing 25 hours of recorded data ... sent from different locations throughout the helicopter.”

The investigators assigned to the case will focus on looking for ways to improve safety and will not determine liability in the crash, Negard said.

“(The team’s investigation) is purely for accident prevention in the future,” he said.

The team will release its findings and safety recommendations to the Navy and the Marine Corps, though investigations can be shared among other agencies in the Department of Defense.

“... Because the UH-60 (Black Hawk) is a common airframe used throughout the services, we would share any information across the DoD if it was determined that a material failure of any kind contributed to the accident,” Negard wrote in an email to The Advocate.