First of two partsStaff writer

For Masatake Okumiya, a lieutenant and dive bomber pilot of the Imperial Japanese Navy, Dec. 12, 1937, was not just another busy day.

On that day, one day before the fall of Nanjing to the Imperial Japanese Army, he took part in a historical incident -- the bombing and sinking of the USS Panay, a U.S. Navy gunboat, in the Yangtze River -- which put Japan-U.S. relations in peril and led furious Americans to coin the phrase "Remember the Panay!" a precursor for some to "Remember Pearl Harbor!"