Nearly a century before the COVID-19 pandemic upended life as we know it, a devastating tuberculosis epidemic was ravaging hospitals across the country. In those dark, pre-antibiotic days, the disease claimed the lives of 1 in 7 Americans. In the United States alone, it killed over 5.6 million people in the first half of the twentieth century. The untold story of some unlikely lifesavers, who in 1929, were called to help by the frantic city officials of New York City, where the epidemic was the worst. Author Maria Smilios tells the story in her new book, "The Black Angels: The Untold Story of the Nurses Who Helped Cure Tuberculosis."