First B-29 Raids on Japan from the Marianas

B-29 raids on the Japanese home islands had in fact begun in June 1944, when aircraft based at Chengdu in China bombed Yawata in northern Kyushu, but range and supply constraints kept the Kanto region out of reach. After US forces captured the Mariana Islands in the summer of 1944 and built airfields on Saipan, Tinian and Guam, Tokyo came within the B-29's radius for the first time. On 1 November 1944 an F-13, the reconnaissance version of the B-29, flew over Tokyo to take photographs.

On November 24, 1944, 111 B-29 Superfortresses of the 73rd Bomb Wing, part of XXI Bomber Command under Brig. Gen. Haywood Hansell and led in the air by Brig. Gen. Emmett O'Donnell, launched from Saipan to attack the Nakajima aircraft engine factory (the Musashi Plant) in Musashino, Tokyo. The plant built engines for the Zero fighter and other military aircraft, was described as the largest of its kind in East Asia, and was the first-priority target of the campaign against the home islands. This was the first major B-29 raid launched from the Mariana Islands against the Japanese home islands; the mission was code-named San Antonio I.

Results were limited due to weather and high-altitude bombing difficulties. The force flew a daylight high-altitude precision mission, but the target was covered by cloud and the bombers met the powerful jet stream, which scattered the bombs; according to English-language accounts only 24 aircraft bombed the primary target, while 64 bombed dock and urban areas instead. The plant was attacked again on 3 December, 27 December and 9 January 1945, among other dates, with similarly poor results, which contributed to the switch to low-level night incendiary attacks under Maj. Gen. Curtis LeMay in March 1945. Even so, the raid of 24 November marked the beginning of the sustained strategic bombing campaign that would devastate Japan's cities and industry over the following months.

According to Musashino City, the plant was raided nine times by the end of the war; more than 200 people connected with the factory were killed and many nearby residents were also caught up in the attacks. In 2011 the city enacted an ordinance designating 24 November, the date of the first raid, as Musashino City Peace Day, marked each year with exhibitions and lectures. Part of the plant site is now the metropolitan Musashino Chuo Park, where explanatory panels describe the air raids and the factory, and a peace information panel also stands at the nearby temple Enmei-ji.