A U.S. surgeon who was diagnosed with Ebola in Sierra Leone and flown to Nebraska over the weekend for treatment, has died, hospital officials said Monday. Martin Salia became the second person to die of the disease in the United States. Thomas Duncan, who contracted Ebola in Liberia and traveled to Texas, died last month. Salia arrived in the United States on Saturday. He was the 10th patient to be treated on American soil and the third at Nebraska Medical Center. Hospital officials had said that he was perhaps sicker than any other patient flown to the United States from West Africa.