The Japanese attack on Pearl Harbor on December 8, 1941 (Asian time) foiled the planned evacuation. The 203 American Marine guards remaining in the Legation Quarter, Tianjin, and Chinwangtao surrendered to the Japanese and became prisoners of war for the remainder of World War II. The civilian foreigners remaining in Beijing were relatively undisturbed until February 1943 when they received a letter ordering them to assemble in the (former) American legation to be transported by railroad to Weihsien Civilian Assembly Center, south of Beijing. The group, ranging in age from six months to 85 years old and including many missionaries, doctors, scholars, and businessmen, were allowed to take only what they could carry and were marched past Chinese crowds assembled to see the humiliation of the foreigners. The foreign population of Beijing was interned in Weihsien until the end of World War II.