A fire hit downtown Old Town late Saturday night. The fire was reported at 274 Main St. just before 10 p.m., a dispatcher at the Penobscot County Regional Communications Center said just after midnight Sunday. That building houses Serenity Salon and Spa as well as apartments, and it is adjacent to several other businesses, including Yamas Bar and Grill and the Penobscot Times, in a block in the heart of the city’s downtown. Dozens of towns have responded to the scene, the dispatcher said. The dispatcher said the scene remained “very active” and Main Street will remain closed at that location for several hours.