San Mateo County public health officials on Thursday announced nine more cases of COVID-19, the disease caused by the new coronavirus, bringing the total to 89.

The number of confirmed cases has more than doubled since the week began, when there were 42 known cases of COVID-19 in the county. It still has only one death, which occurred Sunday.

There were 16 new cases reported Wednesday.

At least three of the 89 cases are known to be in a senior-living facility in Burlingame. A senior-living facility in Menlo Park also has a case.

In adjacent Santa Clara County, which has reported 175 cases, a sixth person died of the disease on Wednesday.

To the north, San Francisco announced 19 new cases on Thursday, bringing its total to 70, with no deaths.

The state department of public health announced the total number of cases California in California had risen to 675, with 16 deaths. Only New York (4,597) and Washington (1,187) have more confirmed cases. The total number in the U.S. climbed to 10,442.