While most of the post-Sandy attention has focused on upper stories, some hospitals—such as the Bellevue Hospital Center complex, near the hard-hit Langone Medical Center—have installed perimeter walls. But a hospital's fixed barriers can be potentially harmful if the staff itself needs to evacuate, said Daniel Collins, a facilities director at Coney Island Hospital in Brooklyn. "We are not comfortable about being able to stay and maintain services with a wall," he said.