OMAHA, Neb. — A surgeon who contracted Ebola while working in his native Sierra Leone died today while being treated in a biocontainment unit at a Nebraska hospital.

Nebraska Medical Center said in a news release that Dr. Martin Salia died as a result of the disease. Hospital spokesman Taylor Wilson said Salia died shortly after 4 a.m.

“Dr. Salia was extremely critical when he arrived here, and unfortunately, despite out best efforts, we weren’t able to save him,” said Dr. Phil Smith, medical director of the biocontainment unit.

Salia arrived Saturday to be treated at the Omaha hospital, where two other Ebola patients have been successfully treated.

Salia, 44, had advanced symptoms when he arrived at the hospital Saturday, which included kidney and respiratory failure, the hospital said. He was placed on dialysis, a ventilator and given several medications to support his organ systems.

Ebola has killed more than 5,000 people in West Africa, mostly in Liberia, Guinea and Sierra Leona. Five other doctors in Sierra Leone have contracted Ebola, and all have died.