330 American B-29s rain incendiary bombs on Tokyo, touching off a firestorm that killed upwards of 100,000 people, burnt a quarter of the city to the ground, and left a million homeless. The B-29 bombers for the Tokyo raid were stripped of their defensive weapons and packed with various incendiary explosives, including white phosphorus and napalm, a new gasoline-based, fuel-gel mixture developed at Harvard University. Tokyo was the first of five incendiary raids launched in quick succession against the largest Japanese cities. Nagoya, Osaka and Kobe were also targeted — with Nagoya getting hit twice within a week. By the end of the war, more than 60 Japanese cities had been laid waste by firebombing. But if the American objective was to shorten the war by demoralizing the Japanese population and breaking its will to resist, it didn't work. What had proven true in Germany proved equally true here: Morale was shaken by bombing, but once the shock passed, the war work went on.