The author responds to an article published in the Journal by Joseph J. Mangano and Janette D. Sherman suggesting that an increase in U.S. deaths shortly after Japan's Fukushima nuclear plant accident could be attributed to radiation from this accident arriving in the United States. The author writes that the cause of these deaths has not been analyzed and that there is no known mechanism for low-dose radiation to cause acute death in infants or adults. The author also notes that the cities under study with the lowest radiation fallout have the highest increases of death rates in the 14 weeks following Fukushima, while the Californian cities that would have received larger doses saw a decrease in death rate growth. He concludes that innumerable factors other than radiation likely are responsible for the bulk of the measured effect.