That brings the US tally to 8

If you want to do some back-of-the-envelop calculations. If you assume the mortality rate is 0.2%-2.0% that implies 400-4000 full-blown cases, with many more incubating or worsening.

That's extrapolating from a tiny sample but Italy went from 6 to 600 cases in a week.

Meanwhile, Spain has reported its first virus death, saying it was way back on Feb 13. We don't know much about the patient but that's three weeks of potential spread, which is far too much to contain.