Medical tents were set up outside Citizens Bank Park in Philadelphia as possible future testing stations for the new coronavirus.
Nearly 7 million people in the San Francisco area were all but confined to their homes Tuesday in the nation's most sweeping lockdown against the coronavirus, even as spring break crowds partied in Florida and tourists lined up to pose for pictures in front of the world-famous "Welcome to Las Vegas" sign.
Arizona, Florida and Illinois pressed ahead with their presidential primaries, recommending such precautions as putting tape on the floor to keep voters a safe distance apart, while Ohio called off its election hours before the polls were to open.
The official reaction to the crisis varied wildly across the U.S., despite new, more urgent warnings from the Trump administration, which called on Americans not to gather in groups of more than 10 and advised older people to stay home.
Coronavirus infections across the country reached about 6,500, and the death toll climbed to at least 109, with more than half of the victims from Washington state. Worldwide, more than 7,900 have died.