CALIFORNIA, United States (AP)— California’s 40 million people were all but confined to their homes Friday in the nation’s biggest lockdown yet, as America’s governors watched with growing alarm as southern Europe buckled under the strain of the coronavirus outbreak.

Gasping patients filled the wards of hospitals in Spain and Italy, and the global death toll surpassed 10,000, with the virus still multiplying and gaining footholds in new corners of the world.

The World Health Organization noted the epidemic’s dramatic speed.

“It took over three months to reach the first 10,000 confirmed cases and only 12 days to reach the next 100,000,” the UN health agency said.

Countries frantically prepared for an onslaught of patients in the coming weeks.

In Britain, the government asked 65,000 retired nurses and doctors to return to work. A convention centre and hotels in Madrid were being turned into field hospitals for nearly 10,000 patients. France’s military worked to build a makeshift medical centre in the hard-hit town of Mulhouse. The US readied military hospitals for civilian use, and more than 4,000 National Guard members were deployed in 31 states to help distribute food, scrub down surfaces and help in other ways.

The Trump administration warned Americans abroad to return home or risk spending an “indefinite” period away. And the income tax filing deadline was moved from April 15 to July 15.

“We’re about to enter into a new way of living here in Los Angeles,” Mayor Eric Garcetti said as California went into lockdown, with people told venture outside only for essential jobs or errands and some exercise. “What we do and how we do it and if we get this right will determine how long this crisis lasts.”