Denton Jr. was shot down and captured in North Vietnam. Months into his imprisonment, he blinked the word "T-O-R-T-U-R-E" in Morse code during a TV interview that his captors permitted.

A receiver would read the flashes ... modern use of Morse code was by Navy pilot Jeremiah Denton, while he was a prisoner of war in Vietnam. In 1966, about one year into a nearly eight-year ...