The Securities and Exchange Commission on Monday asked employees at its D.C. headquarters to stay away from the office because of a potential coronavirus case, becoming the first major federal employer to turn to telework to avoid the spreading virus.

The announcement from the agency, which is charged with monitoring the financial markets, came after a day of turmoil on Wall Street, with the Dow Jones industrial average falling more than 2,000 points. The agency‘s notice, which was emailed shortly after 8 p.m., required employees working on the ninth floor of its office to stay home and encouraged all others to do the same.

“Out of an abundance of caution, effective immediately the SEC is requiring all Headquarters personnel (employees and contractors) who work on the 9th floor to telework,” the email to employees read.

In an emailed statement, the agency confirmed the announcement. “Even with increased telework, the SEC remains able and committed to fully executing its mission on behalf of investors, including monitoring market function and working closely with other regulators and market participants,” the statement said. The agency has more than 4,000 employees across the country.

The email to SEC employees said an employee was treated for respiratory symptoms earlier Monday and was informed by a physician that the person could have the coronavirus. The worker had not been in the office since Thursday.

“To the best of our knowledge, the employee remained asymptomatic during the employee’s time in the building,” the email stated.

The SEC acts as one of the federal government’s primary regulators over the financial markets, which have been in upheaval as the coronavirus outbreak fanned new fears of a worldwide recession. On Monday, stocks fell so sharply, they tripped a “circuit breaker” that halted trading for 15 minutes.