A "critically ill" doctor diagnosed with the deadly Ebola virus infection in Sierra Leone arrived Saturday in the United States for treatment, the Nebraska Medical Center in Omaha, where he will undergo treatment, confirmed. Martin Salia, a native of Sierra Leone and a U.S. legal permanent resident, landed at Omaha's Eppley Airfield at around 4: 00 p.m. EDT (2100 GMT) and was then transported to the Nebraska Medical Center, Xinhua reported. "We have received word he is critically ill -- possibly sicker than any of the other patients transferred from West Africa and treated for Ebola in the United States," the hospital said.