Within hours of the bombing at the U.S. naval base at Pearl Harbor, the Japanese attacked the Philippines.

Within a month, the Japanese had captured the capital, Manila, on the island of Luzon.

American and Filipino prisoners of war captured by the Japanese are shown at the start of the Death March after the surrender of Bataan on April 9 near Mariveles in the Philippines in 1942 during World War II. Starting on April 10 from Mariveles, on the southern end of the Bataan Penisula, 70,000 POWs were force-marched to Camp O'Donnell, a new prison camp 65 miles away. (AP Photo)ASSOCIATED PRESS

American and Filipino soldiers were forced to retreat to the Bataan Peninsula and left without food and supplies. They were ill-equipped to fight the attack. They held on for 99 days with support but then surrendered.

On April 9, 1942, according to history.com, U.S. Gen. Edward King surrendered his troops. The 76,000 prisoners of war – 66,000 Filipinos and 10,000 Americans – were forced to march north 65 miles from the southern end of the Bataan Peninsula to San Fernando and Camp O'Donnell where they were imprisoned. The soldiers were separated into groups of 100 each. It took each group about five days to make the trek.

American prisoners of war carry their wounded and sick as they begin the Death March on Bataan in April 1942. This photo was stolen from the Japanese during their three year occupation of the Philippines. (AP Photo/U.S. Army)ASSOCIATED PRESS

During the march the prisoners were beaten and shot. Some died of starvation and disease while thousands more died at the prison.

Japanese soldiers stand guard over American war prisoners just before the start of the "March of Death" for the soldiers of Bataan and Corregidor in 1942. This photograph was stolen from the Japanese by the Philippines during Japan's three-year occupation in World War II. (AP Photo/U.S. Marine Corps)ASSOCIATED PRESS

“The exact figures are unknown, but it is believed that thousands of troops died because of the brutality of their captors, who started and beat the marchers, and bayoneted those too weak to walk. Survivors were taken by rail from San Fernando to prisoner-of-war camps, where thousands more died from disease, mistreatment and starvation,” according to history.com.

At the end of World War II, the Japanese commander responsible for the march and atrocities at Camp O'Donnell, Lt. Gen. Homma Masaharu, was tried and convicted by the U.S. military commission. He was executed by firing squad on April 3, 1946.