"That is why if you don't act responsibly and stay at home like you have been ordered to do, we will be headed for a situation like we're seeing play out catastrophically every day in New York. This will push our city to the brink," the mayor said.

There have been 949 lab-confirmed cases of COVID-19 in Chicago, the city's health commissioner, Dr. Allison Arwady, said, a number she predicts will surely reach 1,000 tomorrow. Given that there is no vaccine, strict lockdowns like the city is pursuing will prevent the spread. The virus is currently spreading from one person to between two and three. "We have to get that down so that one person on average is spreading to fewer than one person," Arwady said.

"We could be expecting upwards of 40,000 hospitalizations in the coming weeks," Lightfoot said, one of several projections the city, local hospitals, and the state are modeling. "That number is real and it is sobering, which is why we are saying to people, you must stay at home. It is real."