The former U.S. Senator from Alabama, Navy admiral and Vietnam prisoner of war who blinked “T-O-R-T-U-R-E” in Morse Code to alert the world of abuse by his North Vietnamese captors, died on Friday.

Rear Adm. Jeremiah Andrew Denton Jr., USN (Ret.) died in a Virginia Beach, Va. hospice due to complications from a heart ailment, according to local press reports.

He was 89.

Denton — born in Mobile, Ala. and educated at the U.S. Naval Academy — was perhaps best known for his seven and seven month interment by the North Vietnamese in several places including the infamous Hỏa Lò Prison — better known as the “Hanoi Hilton.” He was held with other senior captured U.S. fliers, including U.S. vice-presidential candidate Vice Adm. James Stockdale.

Denton was captured July, 18 1965 when his A-6 Intruder attack fighter was shot down by North Vietnamese troops on his 12th combat mission, according to an oral history recorded by the U.S. Naval Institute in 1976.