Friday marks the 77th anniversary of Pearl Harbor tragedy, which claimed the lives of more than 2,400 Americans.

The Imperial Japanese Navy attacked the U.S. naval base in Pearl Harbor with its warplanes and submarines and sank U.S. four battleships and two destroyers on the morning of Dec. 7, 1941. The next day, former President Franklin D. Roosevelt announced that the U.S. will be entering World War II.

On January 7, 1943, Roosevelt commemorated the Pearl Harbor tragedy in his State of the Union address before Congress in a speech that resonates in the hearts of the people of the U.S. even today.

“First in the importance in the American scene has been the inspiring proof of the great qualities of our fighting men,” he said. “They have demonstrated these qualities in adversity as well as in victory. As long as our flag flies over this Capitol, Americans will honor the soldiers, sailors and Marines who fought our first battles of this war against overwhelming odds the heroes – living and dead, of Wake and Bataan and Guadalcanal, of the Java Sea and Midway and the North Atlantic convoys. Their unconquerable spirit will live forever.”

“A tremendous, costly, long-enduring task in peace as well as in war is still ahead of us. But, as we face that continuing task, we may know that the state of this Nation is good–the heart of this Nation is sound-the spirit of this Nation is strong–the faith of this Nation is eternal,” he added.

Pearl Harbor
A small boat rescues sailors from the USS West Virginia after she had suffered a hit in the Japanese attack on Pearl Harbor, Dec. 7, 1941. Getty Images

From then on, Dec. 7 is remembered as the Pearl Harbor Day every year. Here are a few facts about the tragedy that is forever etched in the pages of American history, taken from Pearl Harbor Warbirds:

1. The Japanese forces, led by Vice Admiral Chuichi Nagumo, traveled 3,400 miles across the Pacific to execute their attack on Pearl Harbor.

2. When they flew over the Pearl Harbor, Japanese Commander Mitsuo Fuchida called out, “Tora! Tora! Tora!” (“Tiger! Tiger! Tiger!”) which was was a message to the entire Japanese navy informing them that they had caught the Americans totally by surprise.

3. The Japanese called the attack the “Operation Hawaii” as they drew their plan. This later changed to “Operation Z.”

4. Sunday was chosen as the day for attack because the Japanese believed that Americans would be more relaxed on the weekend and hence likely to have their guards down.

5. Although the Japanese arrived with 183 war planes, six of them failed to launch weapons. The Japanese navy lost 65 of their men in counter attack from the U.S. and of one was captured.

6. Furthermore, Japan’s intention to inflict maximum damage was foiled by the fact that U.S. aircraft carriers, the primary target of the attack, were not at the base at the time.

7. The Arizona’s band, known as U.S. Navy Band Unit (NBU) 22, had 21 of their members on board the naval battleship USS Arizona when the attack happened. There were no survivors.

8. In fact, over half of the casualties at Pearl Harbor were on the USS Arizona which was hit four times by Japanese bombers. The ship eventually sank into the waters.

9. The Pearl Harbor attack led to eight investigations between Dec. 22, 1941, and July 15, 1946.

10. A floating National Monument was erected on the hull of the sunken Arizona in 1962

11. “Remember Pearl Harbor!” was the rallying cry for the U.S. during World War II. Former President Harry S. Truman ordered atomic bombs to be dropped on Japanese cities of Hiroshima and Nagasaki in 1945, bringing an end to World War II.