A 20-year-old Marine who died in fighting on Tarawa Atoll in 1943 has been identified by a Hawaii lab and is being returned to his family for burial with full military honors, the Pentagon said Friday.

Cpl. James D. Otto of Los Angeles will be buried Tuesday in Arlington National Cemetery. In November 1943, Otto was assigned to Company L, 3rd Battalion, 8th Marine Regiment, 2nd Marine Division, which landed against stiff Japanese resistance on the small island of Betio in Tarawa Atoll, the Defense Department said.

Over several days of intense fighting, about 1,000 Marines were killed and more than 2,000 were wounded. Otto was reported killed in action on the first day of the battle, Nov. 20, 1943.

U.S. service members were buried in a number of battlefield cemeteries on the island. In 1946 and 1947, the 604th Quartermaster Graves Registration Company conducted remains recovery operations on Betio Island. In 1949, a military review board declared Otto nonrecoverable, the Pentagon said.

History Flight Inc., a Florida nonprofit group that has been to Tarawa dozens of times in search of missing Marines, announced in June that it had discovered a long-lost burial trench that was the hasty gravesite of 36 Marines. The remains were turned over to the Defense POW/MIA Accounting Agency in Hawaii in July.

Among them were Otto and 1st Lt. Alexander Bonnyman Jr., a Medal of Honor recipient initially identified while his skeleton was still in the sandy soil by his unique patchwork of gold fillings and crowns.

Bonnyman led his men off Betio Pier against heavy shore fire and attacked a Japanese bunker. More than 100 of the enemy were killed and Bonnyman was mortally wounded in a “heroic stand” on the edge of the bunker.

To identify Otto’s remains, scientists at DPAA’s lab at Joint Base Pearl Harbor-Hickam used dental comparisons, which matched Otto’s records, as well as circumstantial and material evidence, the Pentagon said.