The city of Sendai was the largest population and commercial center of the Tohoku region of northern Honshu island, but lacked specific targets of strategic military significance. The Tōhoku Main Line railway connecting Tokyo with Aomori also ran through the city. The industrial city ofKamaishi was bombed on July 14, 1945, which was also the first air raid experienced in Miyagi Prefecture during the war. The first experience of Sendai with bombing was on March 10, 1945, when three B-29 Superfortress bombers from the Tokyo Air Raid dropped their bomb load on Mount Zaō for unknown reasons, killing 34 civilians, and an additional two B-29 bombers attacked Sendai Airport causing minor damage. On May 25, 1945, a photo-reconnaissance B-29 overflew Sendai at an altitude of 8000 feet, compiling a detailed map of the downtown area of the city. On July 10, 1945, another B-29 made an over flight of Sendai, this time dropping propaganda leaflets warning the residents of the city of its imminent destruction.
The Sendai air raid
On July 19, 1945, 131 B-29 bombers from the USAAF58th Bombardment Wing launched from Tinian island in the Marianas. Several aircraft turned back due to mechanical problems, and 123 aircraft arrived over the target at an altitude of 10,000 feet at just after midnight in the early morning of July 20, 1945. The bombers split into 25 groups of between two and five aircraft each to carpet bomb the densely packed residential center of the city with 10,961 incendiary bombs. The resultant firestorm destroyed most of the historic center of city. As a result of this one attack, 30,000 civilians were killed and 50,000 were injured. A five square kilometer portion of the center of the city was totally destroyed, with 11,933 residences burned. Also lost in the bombing were a number of cultural treasures, include the structures of Sendai Castle, and the Zuihoden mausoleum of Date Masamune. On the other hand, the large Sendai Arsenal, and the structures of the IJA 2nd Division were untouched by the air raid. During the air raid, one B-29 was destroyed on the runway at Tinian and no aircraft were lost over Japan. A year after the war, the United States Army Air Forces's Strategic Bombing Survey reported that 21.9 percent of the city had been totally destroyed. Sendai experienced a number of minor air raids afterwards. On July 12, a single B-29 dropped 36 incendiary bombs on a Sendai suburb. On July 13, July 25, August 9 and August 10, the city and airport were bombed and strafed by United States Navycarrier-based aircraft.