Washington Governor Jay Inslee has taken the extraordinary step of banning gatherings of 250 people or more, as health officials declare the coronavirus outbreak a pandemic. All but eight of the 39 coronavirus-related deaths in America have been in Washington state.

"Public leisure, faith-based or sporting events, parades, concerts, festivals, conventions, fundraisers and similar activities of that dimension are prohibited as we go forward," Inslee said.

The governor warned the ban, which impacts nearly 4 million people, could extend through April, CBS News Correspondent Jonathan Vigliotti reports.

Seattle Public Schools also announced they were closing all 114 schools, impacting 53,000 students.

In Washington, there are now 31 known coronavirus deaths, and more than 365 confirmed cases. Hardest hit are nursing homes, where many residents are elderly and have existing health issues.

Of the 31 deaths, 23 are from one nursing home, the Life Care Center in Kirkland. The center said all of its residents have now been tested and 63 tested positive.

Nationwide, there are more than 1,300 known coronavirus cases. Following Washington's order, Oregon late last night said it too will ban gatherings greater than 250 people.

Worldwide, there have been more than 127,000 cases and 4,700 deaths.