American photojournalist who contracted Ebola while working in West Africa began his journey home for treatment Sunday, while a man who recently arrived in Dallas from Liberia remained in critical condition with the disease.

Ashoka Mukpo, 33, will be the second Ebola patient to be treated at the Nebraska Medical Center’s specialized isolation unit.

Mukpo was working as a freelance cameraman for NBC News in Liberia when he became ill last week. NBC reported Sunday evening that Mukpo had started his journey to the U.S. for treatment and that he would arrive Monday morning. Mukpo’s family said Friday he would be treated in Omaha. Hospital officials said they expected an Ebola patient to arrive Monday, but declined to provide a name.

Mukpo’s father, Dr. Mitchell Levy, told NBC Sunday that his son was “counting the minutes” until he could leave Liberia but that he was not feeling that ill Sunday.