From the article (as well as other places I've read similar things). "Why did so many young adults die? As it happens, young adults have the strongest immune s

From the article (as well as other places I've read similar things). "Why did so many young adults die? As it happens, young adults have the strongest immune systems, which attacked the virus with every weapon possible—including chemicals called cytokines and other microbe-fighting toxins—and the battlefield was the lung. These “cytokine storms” further damaged the patient’s own tissue." The more robust immune response was a large cause of the increased mortality.