 At 16 : 00 on 30 January , a flight of 11 Mitsubishi torpedo bombers from the 751 Air Group , based at Kavieng and staging through Buka , attacked the force towing Chicago . Fighter aircraft from Enterprise shot down eight of them , but most of the Japanese aircraft were able to release their torpedoes before crashing . One torpedo hit the destroyer USS La Vallette , causing heavy damage . Four more torpedoes hit Chicago , sinking her . 
