By the time the U.S. Secretary of State received the intercepted message, the Pearl Harbor attack was well underway.
And others noticed that President Donald Trump had a minor mistake in a tweet he also composed in honor of the day. Much previous years, the ceremony will begin at the chapel on base and conclude with wreath-laying at the Pearl Harbor memorial.
In the days following, a stunned nation tried to grasp the enormity of the loss of 2,500 lives, with 21 American ships and 300 airplanes destroyed or damaged. When asking Congress for a Declaration of War, President Franklin D. Roosevelt famously called the attack "a date which will live in infamy". It was the greatest loss of life ever in an attack on a U.S. warship, the National Park Service says.
America pauses Thursday to remember the 1941 attack on Pearl Harbor that brought the U.S. into World War II. "11/7/1941 Thank you to all military for your courage and sacrifice!"