California’s hospital emergency departments are strangely quiet places these days.

Before the coronavirus hit, tens of thousands of people across the state sought emergency help each day. But in the weeks since the virus began its spread throughout the U.S., those numbers have plummeted by a third to a half, according to physicians overseeing emergency departments in hospitals across Los Angeles County and elsewhere in California.

The steep decline comes amid drastic measures hospitals have put in place to prepare for what health officials fear could be a wave of patients infected by the coronavirus like the ones that have overwhelmed hospitals in New York City and elsewhere.