It began as the odd case of an elderly man found wandering by the side of the Brooklyn-Queens Expressway in June, carrying plenty of cash, a bus ticket, a baseball cap and papers attesting to his name. He seemed well kept, even healthy — apart from the fact that he could not say where, or who, he was.

Sent to Long Island College Hospital in Brooklyn Heights, the man, Celso Heredia, 81, stayed there for several weeks while the police tried to divine what had happened to him. But when that hospital became his temporary refuge, Mr. Heredia was unwittingly swept up in a different drama: the long-running fight over whether the struggling operation will stay open.

On Thursday, the story lines merged with a twist: The police said Mr. Heredia had disappeared from the hospital the day before, the circumstances unclear amid the jockeying over the hospital’s impending shutdown.

Mr. Heredia was reported missing just after 4 p.m. on Wednesday. He was wearing a blue-and-white-striped shirt, bluejeans and black sneakers, and was in “good physical condition, but may require further medical assistance,” according to a police bulletin.