Two American missionaries with the Ebola virus are set to return the U.S. in the coming days to receive treatment, ABC News reports. Dr. Kent Brantly and Nancy Writebol both contracted the virus working to combat the pandemic’s spread in Liberia, which is in the midst of full-scale public health emergency. The virus has killed more than 700 people in West Africa during the outbreak this year.

“The patients will be transported one by one,” sources told ABC News. “With the return of Brantly and Writebol to the United States, it will be the first time that patients diagnosed with Ebola will be known to be in the country,” according to CNN. “Brantly and Writebol are described as being in stable-but-grave conditions, with both reportedly taking a turn for the worse [Wednesday night], according to statements released Thursday by the faith-based charity Samaritan’s Purse.”

Both Brantly and Writebol appear to be headed to Emory University Hospital in Atlanta, Georgia. The hospital “has a specially built isolation unit to treat patients exposed to certain serious infectious diseases,” according to the Atlanta Journal-Constitution. “Set up in collaboration with the Atlanta-based U.S. Centers for Disease Control and Prevention, the unit is physically separate from other patient areas and is one of only four such facilities in the country.”