All 40 million residents in the state of California have been ordered to stay home to prevent the spread of coronavirus.

California Gov. Gavin Newsom on Thursday restricted non-essential movements to control the spread of the coronavirus that threatens to overwhelm the state’s medical system, according to a report from the Associated Press.

“This is a moment we need to make tough decisions,” Newsom said. “We need to recognize reality.”

He said infection rates are doubling every four days in some parts of the state and issued the dire prediction that 56% of California’s population could contract the virus over the next eight weeks.

His move came after counties and communities covering about half the state’s population already had issued similar orders.

People may still leave their homes for walks and exercise and for essential needs such as food and medical care. Restaurant meals can still be delivered to homes.

The state is one of the worst affected in the US after Washington and New York, according to a report by CNN. There are now 910 coronavirus cases in California, including 19 deaths.

Michigan currently has 334 cases, while New York has at least 5,298 and Washington has at least 1,376 confirmed cases.

California is the most populous US state and is the country’s largest state economy.