DES MOINES, Iowa— An Iowa sailor killed in the attack on Pearl Harbor in 1941 will finally be laid to rest in his home state.

The Des Moines Register reports that Navy Signalman 3rd Class William James Shanahan Jr. of Cedar Rapids was killed in the Dec. 7, 1941, attack that pushed the U.S. into World War II, but his remains went unidentified for 78 years.

Shanahan's sister, Mary Lou Shanahan Pierce, donated DNA almost 20 years ago. Finally, in May, that DNA sample found a match and William's remains were positively identified.

A burial with full military honors is planned for Tuesday at the family plot in Cedar Rapids. Gov. Kim Reynolds has ordered all flags in Iowa to fly half-staff from sunrise to sunset to honor Shanahan.

Pierce was just 5 when her brother enlisted in the Navy on Oct. 5, 1940. She said one of her last memories of him was that he would miss her birthday a week later.

Pierce received her brother's remains Friday. She is the only sibling left out of six.

"My mom is very honored to welcome her brother home and have him buried with the rest of our family," said Pierce's daughter, Cheryl Schemmel. "It's what her parents would have wanted."

The Japanese attack at Pearl Harbor destroyed the battleship Oklahoma, the warship Shanahan was on. The ship capsized from multiple torpedo hits, killing 429 crewmen.

Only 35 remains were identified and the rest were buried as “unknown,” according to the Department of POW/MIA Accounting Agency.

Scientists identified Shanahan's remains by using anthropological analysis, circumstantial and material evidence, mitochondrial DNA and autosomal DNA analysis, according to the agency.

Shanahan was born on July 22, 1918. He graduated from high school in 1936 and is remembered as a well-liked man who was proud of his Catholic religion and Irish heritage.

“We just want to honor him. Yes he died a hero, but first and foremost he was my mother’s big brother,” Schemmel said.