The capture of the Saipan  and Tinian (July 1944) gave the allies air bases for the B-29 Super Fortress bombers.  The home islands of Japan were within range and the Allies were now able to initiate sustained bombing of Japan without risking aircraft carriers which would have operated within range of Japanese counter attacks. The B-29 raids began on November 24, 1944. Tokyo was the first target. It consisted of 111 B-29s striking the Musashino aircraft engine plant on the outskirts of Tokyo. The raid was executed as a high-altitude precision raid (but with little effect). As noted in a previous post, the Allies faced major challenges over Japan: high-altitude jet stream winds disrupted bombing accuracy; weather conditions, especially cloud cover, reduced visibility. 

The bombing campaign was focused on Japanese cities. The goal was to destroy key industrial and military targets such as aircraft factories, shipyards, and transportation hubs. The strategy was modeled on the efforts against Nazi Germany which concentrated production in large factory settings.  Japanese industry was decentralized, with small workshops spread throughout urban residential areas. These workshops were as small as home-based, then feeding large operations, still in residential areas, again working up the supply chains to large operations, often located on the edge of residential areas. While there were critical war production located apart from residential areas, e.g. shipyards, other production (ammunition, airplane assembly, weapons, etc) took place in the labyrinth of major city residential areas.

There was an early phase of B-29 bombings on the Japanese home islands as part of Operation Matterhorn. These were planes launched from China. The airfields in China were highly vulnerable. Supplies and logistics had to be flown over the Himalaya Mountains. There were no accompanying fighter escorts. Targets were typically industrial or military facilities near western coastal cities (e.g., steel works, shipyards, aircraft plants). Damage was limited due to small bomb loads, long flight distances, and weather conditions. All in all, the raids were psychologically unsettling, but neither tactically or strategically valuable. 

That began to change in late November 1944.

Before we delve into the aerial bombing campaign, we should consider an event which was seared into the minds of Tokyo and Yokohama residents – an event which shaped emergency preparedness: the 1923 Tokyo earthquake, also known as the Great Kantō Earthquake (the Kantō plane is the broad area on Honshu island that encompasses some of the great cities of Japan)

The earthquake struck on September 1, 1923, at noon when people were cooking lunch. The ~8.0 magnitude earthquake caused extensive damage that was further exacerbated by widespread fires that swept across the wooden neighborhoods of Tokyo and Yokohama. Both cities were devastated as well as surrounding prefectures. The earthquake caused over 130 fires, some of which merged into firestorms. The most infamous was in the Hongō district, where around 38,000 people perished in an open space where they had taken refuge – heat and oxygen deprivation caused by the firestorm being principal causes.

Tokyo’s infrastructure—including roads, bridges, water supply, and railways—was either damaged or destroyed, crippling transportation and communication. Yokohama, then a major international port, was almost entirely flattened. An estimated 105,000–142,000 people were killed, with over 570,000 homes destroyed leaving more than a million people homeless. The event and its aftermath reshaped Japan’s approach to urban planning, emergency preparedness, and national resilience.