What happens to a bustling Main Street in the age of COVID-19? Episode 17 of “Life Under Coronavirus” is an interview with Eileen Tyznar, president of the Greater Sayville Chamber of Commerce, which is putting together a relief fund to get businesses back on their feet. Tyznar talks about Sayville’s nostalgic feel, the issues businesses are having with federal relief, and her plans to get downtown hopping again, no matter how many masks and plexiglass dividers it takes.