A simple question and an honest answer changed American history – and Alexander Butterfield's life.
When President Nixon's deputy assistant appeared before a Senate committee in 1973, a routine question arose about whether conversations in the Oval Office could theoretically have been recorded; he answered yes.
He had personally supervised the recordings ordered by Nixon, which would later lead to the president's resignation in 1974.
Butterfield, born in 1926, came to the White House from the Air Force. After his time in Washington he was a business executive, among other roles. But he never forgot the Watergate scandal.
"I never liked being the cause of everything," he said in 2008.
What do you think?