Overnight, the fire department in Aurora, N.Y., lost a quarter of its volunteers. The sole local doctor found herself reassuring anxious patients that they would still be able to get treatment for heart disease and diabetes. And Jim Orman, mayor of the small upstate village, had to come up with $200,000 to keep the community’s water-treatment plant, operated for nearly a century by Wells College, running. “Do you want a public-health hazard on your hands?” he said. Can a College Town Survive the Closure of Its College?