The American Red Cross, which supplies about 40% of the nation's blood, says donor drives across the country have been cancelled "at an alarming rate" and the organization now faces a "severe blood shortage." "In really good times we may have five days of inventory available for our hospital clients and now we're running at a day or day-and-a-half in some cases," says Chris Hrouda, president of Biomedical Services for the Red Cross. As of Tuesday, the Red Cross says about 2,700 blood drives had been canceled because of concerns about people gathering at workplaces, college campuses and schools — all places where drives typically take place. The organization estimates that's resulted in 86,000 fewer blood donations because 80% of the blood it collects comes from drives held at these locations.