The day this episode is released, December 7th, 2018, marks the 77th anniversary of the event that would send the United States into World War II, the devastating surprise attack on Hawaii's Pearl Harbor.

The U.S.S. Arizona, a Pennsylvania class battleship had been moved from California to Pearl Harbor in an effort to ward off the Japanese from attacking the vulnerable island territory. On December 7th, 1941, the Arizona exploded violently and sank, with the loss of 1,177 officers and crewmen.

Each year, thousands gather at a commemoration ceremony, including survivors of the attack and their families. 2,403 service members and civilians in total were killed during the attack, and 1,178 people were injured. As the years roll on, the ceremony is weighed by the fewer and fewer survivors who are able to attend. This year, only five men who were onboard the Arizona are still living, and none will be able to attend, due to age, health, and the stresses of travel.

It's twilight for the survivors of the Pearl Harbor attack, and today on America's National Parks, we honor their memory, along with the World War II Valor in the Pacific National Monument.