Washington state has reported a seventh death from coronavirus.
All of the COVID-19 deaths in the United States so far have been in the Seattle area.
A spokeswoman for Harborview Medical Center in Seattle said the patient died on February 26. She said the person had been a resident at a suburban Seattle care facility that has reported multiple virus cases and deaths.
The spokeswoman said some hospital staff may have been exposed while treating the patient but officials don't believe other patients were. The hospital staff are being monitored and screened daily.
Researchers at the Fred Hutchinson Cancer Research Center and the University of Washington on Sunday said they had evidence the COVID-19 virus may have been circulating in the state for up to six weeks undetected.
If true, that could mean that there are hundreds of undiagnosed cases in the area.