Since the rubber strike happened in 1936, and there wasn´t too many consumers, and by that time we didn´t import rubber, the only logical explanation is that there was a shortage due to WWII, when america entered the war most of the companies decided and turned to war industry, also many men left their jobs leaving other part of the industry without workers, this caused a shortage in maney products.
The explosion wiped out 90 percent of the city and immediately killed 80,000 people; tens of thousands more would later die of radiation exposure. Three days later, a second B-29 dropped another A-bomb on Nagasaki, killing an estimated 40,000 people.
