Incendiary Bombs
Incendiary bombs were used extensively in WW2. The Nazis used incendiary bombing against Poland, Britain, and the Soviets in the beginning of WW2. The Allies would conduct bombings of their own against German and Japanese targets, annihilating entire swaths of major cities. In Operation Meetinghouse (the bombing of Tokyo) for example, 16 square miles (10,000 acres) were destroyed overnight, killing approximately 100,000 people and leaving approximately one million people homeless. In comparison, the atomic bombing of Hiroshima destroyed approximately 4.7 square miles and killed approximately 80,000 people in the resulting blast and firestorm.