Seventy-five years after being killed in the Pacific during World War II, a Somerville Marine is coming home.

The remains of Marine Private First Class John Mac Donald, which were accounted for in 2016, are returning to his family for a proper burial in Bourne on June 22, according to a news release from the Defense POW/MIA Accounting Agency, which aims to account for servicemen who went missing in war.

“It’s pretty amazing,’’ said Sharon Kelley of Canton, whose father was Mac Donald’s cousin. “I just wish there were more people — relatives on his side or his mother’s side. They were only told that he was missing in action.’’

Mac Donald was 19 years old when he was killed in a battle on the small island of Betio in the Pacific Ocean on Nov. 20, 1943. In an attempt to secure the island, the American forces faced tough Japanese opposition but ultimately succeeded and won the battle. About 1,000 American Marines and sailors were killed.

After being buried in a battlefield cemetery on the island, Mac Donald’s remains were initially declared nonrecoverable following the war. But they were rediscovered in 2015, along with the remains of 34 other Marines, according to the POW agency.

“That is so sad the family never got to know that he’s gonna be buried,’’ Kelley said, because he did not have any children and she does not know of any closer living relatives. “I feel sad that he was only 19.’’

The Marine was born in Somerville and raised in Allston, she said. Kelley said a group of about 10 family members plans to travel to Bourne together for the military funeral.

Kelley said the agency called her son-in-law with the news about the remains after he did an online ancestry kit and they connected him with Mac Donald. Her first reaction: “Well, how do you know?’’

Mac Donald’s remains were identified using anthropological, dental, and chest radiograph analysis, the release said.

“We have to work each [one] case by case, and this is one more family that has closure on their loved one and what happened to him,’’ said Chuck Prichard, a spokesman for the DPAA. “So that makes us all feel good.’’

More than 400,000 Americans died during World War II. Nearly 73,000 of them are still unaccounted for, the agency said.

J.D. Capelouto can be reached at jd.capelouto@globe.com. Follow him on Twitter @jdcapelouto.