Metro lost its third employee to the coronavirus on Sunday when a member of its occupational support team died after being hospitalized for days.

The death was announced to Metro’s 12,000-person workforce in an internal memo from Metro General Manager Paul J. Wiedefeld, which was obtained by The Washington Post.

“I am deeply sorry to report that we have lost another Metro family member to Covid-19,” Wiedefeld said. “This tragic loss reminds us that no one is immune from the deadly coronavirus.”

Wiedefeld said the worker, who was not identified, was part of Metro’s Office of Occupational Health and Wellness. Contact tracing was performed to determine if any workers had interacted with the employee during the illness, the memo said.

Since March, 574 Metro workers have tested positive for the coronavirus, with 506 employees returning to work, according to the transit agency. Another Metro employee who worked as a storeroom clerk died of the virus about three weeks ago after being on sick leave for more than a month.

Joseph Reid, a manager in the Rail Operations Control Center who died in August, was Metro’s first virus-related fatality.

Wiedefeld reminded employees to continue taking health precautions against the virus. He said Metro’s chief safety and medical officers were staying in contact with public health officials and the federal government on the availability of coronavirus vaccines.

“We need to keep wearing masks at all times when we leave our homes and limit social interaction as much as possible until the much-anticipated vaccine becomes available,” he said.

An Employee Assistance Program has been set up for employees who want help or counseling to cope with the three deaths and the stress created by the pandemic, Wiedefeld said.

“In the meantime, please keep our colleague’s family in your thoughts and prayers,” he said.