Nearly 300,000 Americans could be dead from Covid-19 by Dec. 1, University of Washington health experts forecast, although they said 70,000 lives could be saved if people were scrupulous about wearing masks.

A University of Washington model projects the U.S. death toll from COVID-19 will climb to just above 224,000 by Nov. 1, up 16,000 from a prior forecast, due to rising infections and hospitalizations in many states.

The U.S. coronavirus outbreak crossed a grim milestone of over 3 million confirmed cases as more states reported record numbers of new infections, and Florida faced an impending shortage of intensive care unit hospital beds.

University of Washington researchers estimated that 145,728 people could die of COVID-19 in the United States by August 2020.

The U.S. death toll from the coronavirus outbreak could exceed 74,000 by August, according to the University of Washington’s predictive model, often cited by White House officials and state public health authorities.