U.S. column. Duncans crew, however, thinking that Farenholt and Laffey were commencing an attack on the Japanese warships, increased speed to launch a solitary torpedo attack on Gotō's force without telling Scott what they were doing. San Franciscos radar registered the Japanese ships, but Scott was not informed of the sighting. By 23:45, Gotō's ships were only away from Scott's formation and visible to Helenas and Salt Lake Citys lookouts. The U.S. formation at this point was in position to cross the T of the Japanese formation, giving Scott's ships a significant tactical advantage. At 23:46, still assuming that Scott was aware of the rapidly approaching Japanese warships, Helena radioed for permission to open fire, using the general procedure request, "Interrogatory Roger" (meaning, basically, "Are we clear to act?"). Scott answered with, "Roger", meaning only that the message was received, not that he was confirming the request to act. Upon receipt of Scott's "Roger", Helena—thinking they now had permission—opened fire, quickly followed by Boise, Salt Lake City, and to Scott's further surprise, San Francisco. Gotō's force was taken almost completely by surprise. At 23:43, Aobas lookouts sighted Scott's force, but Gotō assumed that they were Jojima's ships. Two minutes later, Aobas lookouts identified the ships as American, but Gotō remained skeptical and directed his ships to flash identification signals. As Aobas crew executed Gotō's order, the first American salvo smashed into Aobas superstructure. Aoba was quickly hit by up to 40 shells from Helena, Salt Lake City, San Francisco, Farenholt, and Laffey. The shell hits heavily damaged Aobas communications systems and demolished two of her main gun turrets as well as her main gun director. Several large-caliber projectiles passed through Aobas flag bridge without exploding, but the force of their passage killed many men and mortally wounded Gotō. Scott—still unsure who his ships were firing at, and afraid they might be firing on his own destroyers—ordered a ceasefire at 23:47, although not every ship complied. Scott ordered Farenholt to flash her recognition signals and upon observing that Farenholt was close to his formation, he ordered the fire resumed at 23:51. Aoba, continuing to receive damaging hits, turned to starboard to head away from Scott's formation and began making a smoke screen which led most of the Americans to believe that she was sinking. Scott's ships shifted their fire to Furutaka, which was following behind Aoba. At 23:49, Furutaka was hit