The fallout in Washington state of the coronavirus, to which two deaths have been attributed, is widening.

The second person to die of COVID-19 was a man in his 70s with underlying health conditions who died on Saturday at EvergreenHealth hospital in Kirkland, according to The New York Times. That is also where the US' first coronavirus death occurred on Saturday, that of a man in his 50s, also with underlying health conditions.

Three other coronavirus cases were confirmed in King County, according to the Times, all at EvergreenHealth.

They are three senior citizens — two women and a man. All were in critical condition with underlying health issues. The four new cases all were residents of a nursing facility in Kirkland, according to the Times, where two others had tested positive for the virus.

"This is a tragic loss of life and we share our heartfelt condolences with the family," said Dr Jeff Duchin, Health Officer for Public Health – Seattle & King County, said in a press release Saturday. "While the vast majority of cases of COVID-19 are believed to be mild, the virus can be a very serious infection that can lead to death."

Governor Jay Inslee said: "I know this news is alarming, but we are doing everything possible to make sure the public is safe. Earlier today I declared an emergency proclamation directing state agencies to use all resources necessary to prepare for and respond to the outbreak. The best thing people can do to help is remain informed and take routine health precautions."

Also on Sunday morning, public health officials in the county, where Seattle is located, confirmed two new cases of coronavirus unrelated to the nursing facility.

The Lake Washington Institute of Technology in Kirkland, where 16 students and one faculty member were possibly exposed to the virus, will be closed Monday and Tuesday to disinfect and clean the campus, according to a statement by Amy Morrison, the school's president.

Hazen High School in Renton will be closed for deep cleaning Monday out of an "abundance of caution" after a student and parent were tested for the virus on Saturday. Test results are not in, but the school district said it learned about the illnesses from the student's parent Sunday morning and immediately contacted King County public health officials.

Jackson High School in Mill Creek also will be closed Monday after a student tested positive for coronavirus. That student is isolated at home and is "doing well", according to Snohomish County health officials.

Last week, Bothell High School was closed on Thursday and Friday due to virus concerns. The Bothell closure came after a family member of a school employee showed some coronavirus symptoms; both had traveled abroad. The school is set to reopen Monday after the family member tested negative for the virus.

Zi Long, a resident of Redmond, told China Daily he wouldn't sign a petition calling for school closures because he didn't think "fear should be a factor", but said he agrees that large gatherings should be canceled.

A Bellevue parent who did not want to give his name said he was not panicking about the current situation but was concerned about the possible spread of the virus in a school setting.

"We have two kids and really can't risk it," he said.

According to Seattle-based King5 News, the only lab in the state that can test for the virus began running tests Saturday morning and has become a 24/7 operation.

"We are fortunate to have one of the best public health agencies in the nation, and we are pulling all available resources into the fight against COVID-19," said King County Executive Dow Constantine. "I urge businesses and families to plan and take precautions."

William Hennelly in New York contributed to this story.