Callaghan was a US Admiral who served in the South Pacific. In November 1942 he was sent with a force of heavy cruisers the San Francisco (his flagship) and the Portland and light cruisers the Helena, Juneau and Atlanta. The San Francisco did not have radar and had to rely on information passed on by the Helena. The only method of communicating was the TBS (Talk Between Ships) but there was so much interference on the system that many valuable messages were lost. The Helena’s radar spotted a Japanese force off Savo Island but the Americans lost their chance to fire their torpedoes first. The Japanese used their spotlights and immobilized the Atlanta with fire power. The action became very confused and the San Francisco hit the Atlanta mistaking it for an enemy vessel. The San Francisco came under fire from the Kirishima and her bridge was hit. Callaghan died immediately.