The governor of California declared a state of emergency as the number of cases there shot up to 54, the most in the United States, and Facebook said that a worker in its Seattle offices had tested positive. We have live updates and a video of what the virus’s impact looks like from space.

Nearly 300 million students are now out of classrooms worldwide, and the outbreak — which has killed more than 3,200 people and infected more than 95,000 in dozens of countries — is increasingly disrupting work, travel and leisure on multiple continents.

Here’s a sampling:

China: Local governments across the country are erecting barriers between neighborhoods in an effort to stop people from spreading the virus. Officials in the northern city of Tianjin call the steel sheets the “Blue Great Wall.”

Events: The London Book Fair and the Geneva International Auto Show are among the events that have been canceled over coronavirus fears. (The Summer Olympics in Tokyo are still a go, at least for now.)

The arts: The Louvre in Paris reopened, with caveats, after closing for three days, and some wonder if a highly anticipated exhibition of Raphael paintings that opens in Rome today will go on as planned.