AP

Former Alabama Sen. Jeremiah Denton, who survived 7½ years as a prisoner of war in North Vietnam and alerted the U.S. military to conditions there when he blinked the word "torture" in Morse code during a television interview, died Friday. He was 89.

Denton's grandson, Edward Denton, said he died about 8 a.m. at a hospice facility in Virginia Beach, Va., surrounded by family. Edward Denton said his grandfather had been in declining health for the past year and died from heart problems.

Denton, a retired Navy rear admiral, in 1980 became the first Republican elected to the U.S. Senate from Alabama since Reconstruction, but he narrowly lost a re-election bid six years later.

As a senator, he was a strong advocate of conservative causes and backer of the Reagan administration. But the iron will that served him in such good stead in captivity gave rise to criticism that he was too rigid as a politician.

Denton first received wide notice as a POW with an unbending patriotic commitment, despite torture and the horrors of years of captivity. He called his book about the experiences "When Hell Was in Session."

In June 1965, the Mobile native and father of seven began flying combat missions for the U.S. Navy in Vietnam. The next month, on July 18, he was shot down near Thanh Hoa.

Captured, he spent the next 7½ years in several North Vietnamese prisoner of war camps, including the infamous "Hanoi Hilton." Four of those years were spent in solitary confinement in a tiny, stinking, windowless cell.

"They beat you with fists and fan belts," he told the Los Angeles Times in 1979. "They warmed you up and threatened you with death. Then they really got serious and gave you something called the rope trick." The use of ropes — to cut off circulation in his limbs — left him with no feeling in his fingertips and intense muscle spasms, he said.

It was Denton who provided the first direct evidence of torture by his captors when, apparently unbeknownst to them, he blinked his message in Morse code in a 1966 interview done with him in captivity.

In the tape, made by a Japanese interviewer and intended by the North Vietnamese as propaganda, Denton also confounded the captors by saying that he continued to fully support the U.S. government, "and I will support it as long as I live." He was tortured again.

"In the early morning hours, I prayed that I could keep my sanity until they released me. I couldn't even give in to their demands, because there were none. It was pure revenge," Denton wrote.

He said his captors never brought him out for another interview. But with the war's end drawing closer, he was released in February 1973.

He was the senior officer among former POWs who stepped off a plane into freedom at Clark Air Base in the Philippines. Denton epitomized the military spirit as he spoke for the returning soldiers: "We are honored to have had the opportunity to serve our country under difficult circumstances. We are profoundly grateful to our commander-in-chief and to our nation for this day. God bless America."

His words and bearing, beamed back to his country by television, gave heart to the military at a time of increasing uncertainty and bitter division over the course of the war.

The tape he had made in 1966 was widely seen, and U.S. intelligence experts had picked up the Morse Code message. But Denton theorized later that his captors likely figured it out only after he was awarded the Navy Cross — the second-highest decoration for valor — for the blinks in 1974.

He was promoted to rear admiral and retired from the Navy in November 1977. Denton then turned to politics, despite having no experience running for a statewide political office. With Ronald Reagan atop the GOP ticket, Denton became the first Republican elected to the Senate from Alabama since the Reconstruction era following the Civil War.

In Washington, he was a Reagan loyalist, a defender of military might and an advocate for a return to traditional family values and conservative stands on moral issues. But critics said his rigid stands left him no room for political compromise and lessened his influence, limiting his ability to help Alabama.

Denton lost his re-election bid in 1986 by only a fraction of a percentage point. After his defeat, Denton founded the Coalition for Decency and lectured about family causes. Denton also launched a humanitarian outreach to needy countries through his National Forum Foundation, which arranged shipments of donated goods.

In later years, Denton lived in Williamsburg, Va., but he still appeared at patriotic gatherings. In November 2008, an emotional Denton watched at Battleship Memorial Park in Mobile, Ala., as a newly restored A-6 Intruder fighter/bomber — like the one he flew over North Vietnam — was rolled out.

The aircraft had been acquired from the National Museum of Naval Aviation in Pensacola for display in the Alabama park in Denton's honor.

Denton's grandson, Edward, said that on one hand, Denton was a normal grandfather who enjoyed taking his grandchildren fishing aboard his boat in Mobile. "On the other hand," he said, "he was a war hero and someone who set an example for being what being a good, patriotic American is all about."