Almost 75 years after the attack on Pearl Harbor, the remains of five U.S. sailors who perished when their battleship was sunk there have been identified, the Pentagon said Monday.

The five men, who were exhumed last year from their graves in Hawaii and examined in special military laboratories, were among 429 sailors and Marines killed when the USS Oklahoma was torpedoed and capsized.

They had been buried as “unknowns.”

The battleship’s loss of life at Pearl Harbor was second only to the 1,100 lost on the USS Arizona, whose wreck remains a hallowed Pearl Harbor historic site.

The men identified were Chief Petty Officer Albert E. Hayden, 44, of Mechanicsville, Md., in St. Mary’s County; Ensign Lewis S. Stockdale, 27, of Anaconda, Mont.; Seaman 2nd Class Dale F. Pearce, 21, of Labette County, Kan.; Petty Officer 1st Class Vernon T. Luke, 43, of Green Bay, Wis.; and Chief Petty Officer Duff Gordon, 52, of Hudson, Wis.

The USS Oklahoma was sunk by several bombs and torpedoes during the Japanese attack on Pearl Harbor on Dec. 7, 1941. A total of 429 crew died when the ship capsized. (National Archives and Records Administration)

The Oklahoma had a complement of about 1,300, including 77 Marines.

Hayden was a World War I veteran. He had been in the Navy since 1917 and had served on the battleship USS Texas in the North Sea, according to a 1942 newspaper account.

Gordon, at 52, was probably among the oldest sailors on the Oklahoma, and Pearce, at 21, one of the youngest.

A destroyer escort was named for Stockdale later in World War II and christened by his mother and grandmother, niece Trudy Ritz said.

Ritz, 71, of Tualatin, Ore., said she was born after her uncle died, but said he was her grandmother’s only son. She said she is grateful for the memories of her uncle that were shared through family.

The identifications came about through advances in forensic science and genealogical help from family members, Air Force Lt. Col. Holly Slaughter, spokeswoman for the Pentagon’s Defense POW/MIA Accounting Agency (DPAA), said in an email.

They are the first to come from a project that began last April when the Defense Department announced plans to exhume an estimated 388 of the Oklahoma’s unknowns.

The effort was sparked after researcher and Pearl Harbor survivor Ray Emory, in 2003, used National Archives files to get officials to dig up a casket thought to contain an Oklahoma sailor’s remains.

That sailor was duly identified, and in 2007 a second casket was unearthed and the remains within were also identified as an Oklahoma sailor.

The remains were returned to their families.

The latest identifications were made by comparing prewar dental records with the teeth of the exhumed sailors, Slaughter said.

During the Dec. 7, 1941, Japanese attack on Pearl Harbor, which plunged the U.S. into World War II, many Oklahoma sailors jumped from the ship as it rolled over in about 50 feet of water.

But hundreds were trapped below decks and died.

In the months, and years, after the attack, the handling of the crew’s remains was plagued by error and poor record-keeping.

Most of the dead were found in the wreckage during the operation to salvage the Oklahoma, according to a memo by DPAA historian Heather Harris.

By then, the remains were skeletal.

By 1944, the jumbled skeletons, saturated with fuel oil from the ship, had been buried as unknowns in two Hawaiian cemeteries, Harris’s report said.

Three years later, they were dug up and taken to a military laboratory near Pearl Harbor for attempted identification.

The chief tool then also was the comparison of the dental records with the teeth of the deceased. And 27 tentative identifications were made. But they were rejected as incomplete by authorities.

Gordon, Hayden, Luke, and Stockdale were among those 27, Slaughter said in an email.

In 1949, all the remains were formally declared unidentifiable. And by 1950, they had been reburied in the National Memorial Cemetery of the Pacific, often called the Punchbowl, in Hono­lulu. They rested there until last year.

“That’s the sad part,” said Ritz, Stockdale’s niece. Had those identifications been approved in 1949, her family might have had her uncle’s remains, a proper grave and some closure. “But that didn’t happen.”

The first exhumations took place June 8, and the last four caskets were dug up Nov. 9.

Sixty-one rusty caskets, still with their carrying handles, were retrieved from 45 graves. The caskets were heavily corroded and had to be forced open.

After the remains were removed, they were cleaned and photographed, and most of them were flown to the DPAA lab in Nebraska for further analysis. Skulls were retained in a DPAA lab in Hawaii, where forensic dentists are based.

The Pentagon said it wants to return as many remains as it can to the families.

They “have been waiting over 74 years,” Slaughter said.