On July 18, 1965, U.S. Navy Comdr. Jeremiah A. Denton, Jr., was shot down while leading an air attack on a military installation in North Vietnam. Captured by the North Vietnamese that day, he remained a prisoner of war for seven years and seven months, enduring years of solitary confinement and brutal mistreatment.

On May 2, 1966, as part of a propaganda campaign, the North Vietnamese arranged for him to be interviewed for television by a Japanese reporter. Asked about his views on the actions of the U.S. Government, he strongly affirmed his government’s position, in defiance of his captors’ instructions; he prepared himself for a torture session that was sure to follow.

While speaking on camera, he blinked in Morse code the word “T-O-R-T-U-R-E.” Eventually, the videotape was widely circulated and reviewed by U.S. Naval Intelligence. Denton’s one-word report, delivered in Morse code, was the first clear confirmation received by U.S. Intelligence that American POWs were, in fact, being tortured.

He later speculated that the North Vietnamese did not learn of his blinking message until 1974. The taped interview is among the holdings of the Special Media Archives—Records of the Central Intelligence Agency.

Promoted during his captivity, Captain Denton was released on February 12, 1973. After retiring from the U.S. Navy as a rear admiral, he was elected to the U.S. Senate where he served from 1981 until 1987.