BOSTON — Health officials in Massachusetts say confirmed coronavirus deaths have surpassed 10,000, and they’re cautioning that the actual toll is likely much higher because of fatalities not attributed to COVID-19.

Massachusetts has the sixth-highest death toll in the nation behind New York, Texas, California, New Jersey and Florida.

Massachusetts’ pandemic nightmare began in late February, when a cluster of cases blamed on a conference at a Boston hotel organized by the Biogen biotech company seeded not just the state but the nation with the virus.

As of Thursday, the state — a Northeast hot spot — also had 174,953 confirmed cases, with 661 people currently hospitalized.

The biggest caseloads and death counts have been in and around Boston, in places where the Black and Latinx populations are largest, including Lawrence, Chelsea, Everett and Revere. But worrisome rates of infection increasingly have been reported around the state.