On August 7 1942, immediately upon receiving information of American landings on Guadalcanal and Tulagi, Mikawa, then Commander in Chief on Rabaul, set out with a force of five heavy cruisers and two light cruisers. He managed to get through the Slot undetected on the next day and that night took CRUTCHLEY’s Southern Force and Riefkohl’s Northern Force completely by surprise. This was partly due to bad communications between the Americans. The Battle of Savo Island resulted in the Japanese arriving home safely with no casualties while the Americans lost four cruisers and 1023 men. Mikawa however had not attacked the undefended US supply ships believing mistakenly that US carriers were in the area.