“There’s nowhere to hide,” said Diane Swonk, chief economist at Grant Thornton in Chicago. “This is the deepest, fastest, most broad-based recession we’ve ever seen.”

Some of the new jobless claims represent freshly laid-off workers; others are from people who had been trying for a week or more to file. “We’re still playing catch-up on multiple fronts,” Ms. Swonk said.

Each day seems to bring unwelcome milestones. On Wednesday, the Commerce Department reported the steepest monthly drop in retail sales since record-keeping began nearly 30 years ago, and the Federal Reserve said industrial production had recorded its biggest decline since 1946.

The mounting unemployment numbers seem certain to fuel the debate over how long to impose stay-at-home orders and restrictions on business activity. President Trump has said some measures should be relaxed soon because of the impact on workers. “There has to be a balance,” he said at a press briefing Wednesday evening. “We have to get back to work.”