At 7:38 am of 18 April, while the task force was still about 650 miles from Japan, it was sighted by Japanese picket boat which radioed an attack warning to Japan.Doolittle and Hornet skipper Captain Marc Mitscher decided to launch the B-25s immediately—10 hours early and 170 miles farther from Japan than planned. This was the only time that United States Army Air Forces bombers were launched from a U.S. Navy aircraft carrier on a combat mission.
The aircraft began arriving over Japan about noon and bombed 10 military and industrial targets in Tokyo, two in Yokohama, and one each in Yokosuka, Nagoya, Kobe and Osaka.While the material damage inflicted by Doolittle’s raiders proved small, and the early-warning line would be restored by an infusion of vessels to replace the ones lost, the effect of the air raid on the Japanese capital itself was enormous.
