The international Red Cross has reported that a local employee in Sierra Leone has died of the Ebola virus. The male nurse is the first Red Cross worker or volunteer to succumb to the disease there.

The International Federation of Red Cross and Red Crescent Societies said that the nurse worked in an Ebola treatment center in Kenema, the country’s third largest city. The unidentified man died on Tuesday and was confirmed to have been infected by the virus.

On Thursday, the organization said they were investigating whether the man was infected at home or while working at the treatment center. There are 29 people who had contact with the man currently under observation for symptoms of the virus.

The outbreak, which originated in West Africa, has grown to over 20,000 cases worldwide, according to the CDC. Sierra Leone has been hit hardest by the year-long outbreak, with over 10,000 of the cases occurring there.