When Hurricane Irma smashed into Key West, Fla., author Shel Silverstein’s historic home was nearly leveled. But it was another home in his neighborhood that had Brewster Chamberlin, a writer and historian, worried.

His friend Sandra Spanier was also nervous. Not only because she feared for Mr. Chamberlin, who weathered the hurricane at home with his wife, but also because they shared a discovery that few people knew about.

In May, she and Mr. Chamberlin found Ernest Hemingway’s first short story — an untitled, previously unknown work that he wrote at the age of 10 — in the archives of the Bruce family, longtime friends of the Hemingways. It was only a few months after she’d first touched the stained brown notebook containing the story, and now this rare artifact could be blown off the island entirely. “I was really terrified,” said Ms. Spanier, the general editor of the Hemingway Letters Project and an English professor at Penn State University.