If you wondered why flags are being flown at half-mast today, it is in recognition of December 7, 1941, when American military base in Pearl Harbor was attacked by the Japanese Navy and air force. The American pacific fleet was caught by surprise, and there was a tremendous loss of life, 2,403 Americans were killed in the attack.
If you go to Hawaii today, you can visit the sunken battleship USS Arizona, which is a memorial in Pearl Harbor built over the sunken ship and the 1,177 crew members who are entombed there. In total, 18 U.S. ships were sunk or damaged, and 188 U.S. aircraft destroyed in the attack.
The attack on Pearl Harbor brought about a declaration of war by the United States on Japan.
December 7 is a day to remember those who were lost on that day.