Hi all — my turn to ask a question of you, because I'm not steeped in the Pearl Harbor literature.
Pearl Harbor was attacked by the Japanese starting around 7:45AM Hawaiian time. When did the news agencies on the American mainland start broadcasting information about the attack? (A colleague of mine remembers, as a child, listening to the Jack Benny Show on the radio in 1941, and remembers it being interrupted with news of Pearl Harbor, if that is helpful.)
I am curious about the speed of "major" news information at that time. FDR seems to have gotten news of it around 1:30pm, which would imply a little over an hour after it started (if my time zone math is right). But I don't know when the first broadcasts would have began, and am curious.
So the first official word from the White House actually followed relatively quickly.
FDR's Press Secretary addressed the WH Correspondents with his first statement at about 2:30pm East Coast time. With updates following every 15-30 minutes as they got them from Oahu and decided what to share. This was even before the full cabinet was brought in which would not occur until about 9pm, with Hill leadership to follow.
It also made it in time for the evening BBC news broadcast on GMT(so another 5 hours ahead) at 9PM which is how Churchill first heard the news.
But at least according to the book I have closest at hand (my Kindle version of Toll's Pacific Crucible), it was indeed shortly after confirmation by the White House that reports began to run.
So your friend is absolutely right that the Jack Benny Show was likely interrupted by a new report related to the attack.
However per this: http://www.radiomemories.com/thejackbennyshow.html
He was in the Sunday evening slot so while it happened, it was probably an update or clarification though if one had been away from the radio all day it is possible that was their first word, or the announcement that the President would address Congress the next day.