The Japanese attack began at 11:13 as the carriers, stationed apart, and their escorts opened fire with anti-aircraft guns. The four torpedo planes which attacked "Yorktown" all missed. The remaining torpedo planes successfully employed a pincer attack on "Lexington", which had a much larger turning radius than "Yorktown", and, at 11:20, hit her with two Type 91 torpedoes. The first torpedo buckled the port aviation gasoline stowage tanks. Undetected, gasoline vapors spread into surrounding compartments. The second torpedo ruptured the port water main, reducing water pressure to the three forward firerooms and forcing the associated boilers to be shut down. The ship could still make with her remaining boilers. Four of the Japanese torpedo planes were shot down by anti-aircraft fire.