Cups & Company has closed amid coronavirus concerns, according to general manager Kathy Chung. The popular coffee spot, which has a loyal following among senators and staffers on Capitol Hill, hopes to reopen April 6.

You may have heard of the Waffle House Index. It’s an informal way the Federal Emergency Management Agency predicts the impact of natural disasters such as hurricanes and tornadoes.

Former FEMA Director Craig Fugate used the term in 2011 while surveying tornado damage in Joplin, Missouri. Because the famous diner is known for staying open under extreme weather and communicating with employees about disaster preparedness, the federal government can gauge if an area will be particularly hard hit by tracking the restaurant’s operations. For instance, if the diner is fully open, the index is green. But the index is yellow if Waffle House is open but offering only a limited menu.

While not exactly the Waffle House, Cups has been a mainstay (and a never-ending supply of coffee) for bleary-eyed and beleaguered Senate staffers facing long days on Capitol Hill. But the threat of coronavirus has left the Hill sparsely populated, with many staffers working from home.

Things “have been very slow here,” Chung said of business in the basement of the Russell Senate Office Building. The shop also wants to do its part to prevent the spread of COVID-19, she added.

So as of 1:30 p.m. Tuesday, Cups has shut down for the next three weeks and plans to reopen April 6, after receiving permission from the Architect of the Capitol. Meanwhile, workers will be compensated, Chung said.

The closure comes just six months after Cups reopened, to the delight of Senate staffers, following a renovation and expansion.

Among those often spotted sipping from a Cups cup is Sen. Ted Cruz. “Cups coffee is the best,” the Texas Republican tweeted last year.