On August 27, 1943, the island was attacked by American forces. The Japanese lost 345 killed and 500 wounded during the fighting for the island. Eventually, General Sasaki withdrew from Arundel and Gizo on September 20–21, 1943.[3] Kolombangara had already been liberated by the American invasion of Vella Lavella, and, at the end of September, the Japanese began to evacuate their last base in the New Georgia islands.[4]