Wednesday marks the 75th anniversary of the Japanese attack on Pearl Harbor in Hawaii.

The attack beginning at 7:55 a.m left, according to NBC, 2,403 Americans dead – 2,335 service members and 68 civilians – and launched World War II. By the time the attacks were over, 21 ships were sunk or damaged and more than 300 aircraft were broken or destroyed.

President Franklin Delano Roosevelt declared Dec. 7 “a day which will live in infamy” in an address to the nation when he asked Congress to declare war.

According to NBC, about 4,000 people are expected to attend the commemoration ceremony at Pearl Harbor.

“From the men and women who gave their lives on that infamous day to the thousands of Americans who have since given the ultimate sacrifice, we should be thankful for the service, dedication, and heroism our armed forces have continually displayed throughout our history,” social studies teacher John Chisholm said.

Ceremonies and a moment of silence will be held at Kilo Pier and at Hickam Air Force Base, joint bases to Pearl Harbor, to mark the time Japanese planes hit their first targets in the harbor.

Japanese Prime Minister Shinzo Abe will not attend the ceremony but will visit Pearl Harbor with President Barack Obama at the end of December, according to the New York Times, marking the first visit by a leader of the country to visit the site.

“Freedom is never free and we need to honor those who have come before to ensure we can continue to enjoy the prosperity of our nation,” Chisholm said.