Due to the Japanese attack of Pearl Harbor on 7 December 1941, the United States entered the Pacific part of World War II. Along with this military effort was the work of the Flying Tigers in Kunming, China, under Claire Chennault. Nurses were thus needed in China to serve the U.S. Army. These nurses were recruited among the Chinese nurses residing in China, particularly the English-speaking nurses that fled Hong Kong (a British colony) to free China due to the Japanese invasion of Hong Kong on 8 December 1941. The Hong Kong nurses were trained by the Department of Medical Services (directed by Dr. Percy Selwyn Selwyn-Clarke) of the Government of Hong Kong. They took up Nursing positions at the Flying Tigers (Rebecca Chan Chung 鍾陳可慰, Daisy Pui-Ying Chan 陳培英), U.S. Army (Rebecca Chan Chung 鍾陳可慰, Daisy Chan 陳培英, Cynthia Chan 陳靜渝), Chinese Red Cross (Elsie Chin Yuen Seetoo, Irene Yu 余秀芬) and China National Aviation Corporation (Rebecca Chan Chung 鍾陳可慰, Irene Yu 余秀芬). Cynthia Chan 陳靜渝 is the elder sister of Anna Chan 陳香梅 (Mrs. Chennault).