Jeremiah Denton, a former Navy rear admiral and U.S. senator from Alabama who survived nearly eight years of captivity in Vietnamese prisons, has died aged 89.
In 1965, Denton was captured by North Vietnamese forces after his fighter jet crashed. He was then forced to appear in a propaganda video about his treatment and America's role in the conflict.
But Denton got the best of his captors, blinking the word "torture" in Morse code as a signal to U.S. military intelligence that his comments were being made under duress.
When his captors learned what he'd done, he was brutally tortured. But for his courage and cunning, President Johnson awarded Denton the Navy Cross.
A YouTube user has uploaded the clip.
Here's what he blinked:
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