Santiago J. Erevia receives the Medal of Honor, the U.S. military’s highest award for valor, from President Obama on March 18, 2014. (Bill O'Leary/The Washington Post)

Santiago J. Erevia, an Army specialist who braved unremitting hostile fire to single-handedly destroy four enemy bunkers in a search-and-clear mission during the Vietnam War, an act of heroism recognized nearly half a century later with the Medal of Honor, died March 22. He was 70.

His death was announced by the Bexar County Veterans Service Office in San Antonio, where Mr. Erevia lived. Other details were not immediately available.

Mr. Erevia was one of two dozen veterans who received the Medal of Honor in an unusual White House ceremony led by President Obama in March 2014. They were selected for the award after a Pentagon review, mandated by Congress in 2002, of past discrimination in the bestowal of the military’s highest honor for valor.

Each recipient had previously received the Distinguished Service Cross, the second-highest military award, for heroism in World War II, the Korean War or the Vietnam War. Seventeen of the men, among them Mr. Erevia, were Hispanic. One was African American, and one was Jewish. Only three were alive to receive the medal in person.

Mr. Erevia’s medal recognized his actions on May 21, 1969, when he was a 23-year-old radio-telephone operator serving in South Vietnam with the 101st Airborne Division. He and his unit were dispatched to Tam Ky, a town on the South China Sea, and tasked with rooting out a contingent of North Vietnamese concealed in bunkers and other hideaways.

“I thought I was going to get killed instantly,” Mr. Erevia recalled. (Courtesy of U.S.Army)

Starting from the edge of a rice paddy, the men were faced with crossing 100 yards or more of open land. As they advanced, enemy troops, some of them camouflaged with tree branches and leaves, emerged from spider holes and trenches and began firing.

Mr. Erevia was ordered to deliver first aid to the wounded but came under attack.

“Although he could have taken cover with the rest of the element, he chose a retaliatory course of action,” according to his Medal of Honor citation. “With heavy enemy fire directed at him, he moved in full view of the hostile gunners as he proceeded to crawl from one wounded man to another, gathering ammunition.”

With another soldier, Patrick Diehl, Mr. Erevia sought cover behind a tree.

“We were back to back,” Mr. Erevia once told an interviewer. “I said, ‘Diehl, do you see anything to your side?’ He never answered. And I said, ‘Diehl!’ I turned around and he was laying on the ground with a bullet hole square on his forehead.”

Mr. Erevia concluded that, if he was going to perish, he would do so fighting, and he advanced toward the North Vietnamese, ignoring their fire.

“I zigzagged, firing my M-16,” he told NPR in 2014. “I thought I was going to get killed instantly.”

He made his way to the first of four bunkers, where, according to the citation, he dropped a grenade into the fortification and destroyed it. He moved on to the second and third bunkers, destroying both with his last grenades.

When he reached the fourth bunker, an enemy soldier was firing into the air and put a bullet through Mr. Erevia’s jacket, according to an account released by the Army.

“I was about maybe two or three feet away from him,” Mr. Erevia told NPR. “And then I shot him point blank with my M-16, and end of story.”

Mr. Erevia later helped evacuate the wounded and the dead. He said that for years he was haunted in his sleep by images from that day.

A fellow soldier, John “Mac” MacFarland, was asked to draft a Medal of Honor citation for Mr. Erevia. Years later, MacFarland told the Los Angeles Times that he had spent weeks writing the account of his comrade’s heroism. When Mr. Erevia did not receive the medal, MacFarland blamed what he feared was the insufficiency of his writing skills.

Other soldiers speculated that Mr. Erevia had been passed over for the medal not because of discrimination but because he had not been wounded or killed, according to the San Antonio Express-News.

But in 2014, Mr. Erevia’s son Jesse told The Washington Post that the family “wondered why he didn’t receive it the first time, and thought it may have been because of his name.”

Months before the White House ceremony, President Obama phoned Mr. Erevia to inform him of his selection for the medal.

“He said that, for some reason, I was overlooked, but that he was making it right,” Mr. Erevia recalled. “I said, ‘Thank you very much, sir.’ ”

Santiago Jesus Erevia was born in Corpus Christi, Tex., on Dec. 15, 1945. He left high school and worked as a cotton laborer, cook and soda deliveryman before joining the Army.

“I thought maybe I could better myself,” he told the Los Angeles Times.

Besides the Medal of Honor, his awards included the Bronze Star Medal, the Purple Heart, the Air Medal and the Army Commendation Medal.

After his Army service, Mr. Erevia served in the Texas National Guard and became a postal carrier. He was married to Leticia Lopez and had four children, one of whom, Roland, served in the Army in the 2003 Iraq War.

Mr. Erevia said he told his son not to “try to be a hero.”

“Just duck and hit the ground and raise your rifle and shoot toward the enemy,” he counseled him. “I was put into the situation that I could not get out.” If his son did not have to put his life “in the hands of God,” Mr. Erevia said, he should not.

An earlier version of this obituary incorrectly reported that Mr. Erevia was born in Nordheim, Tex. He was born in Corpus Christi, Tex.