Lucy Yu wasn’t sure if she had smoke in her lungs or was having an anxiety attack. She needed fresh air.

Five days earlier, on the Fourth of July, she had raced out of her bookstore in Manhattan’s Chinatown as it filled with smoke. A fire had broken out in an upstairs apartment, threatening to destroy all she had built.

Now Ms. Yu was back, and had to face it. She had assembled a team of friends to pack up the books that weren’t damaged beyond repair and put them in storage. By the last bag, she had pain in her chest.

She walked outside and sat down on a stoop next door, as her friends comforted her and brought her water.

Her once-vibrant store, Yu & Me Books, needed a gut renovation to remove mold and smoke residue. The ceiling was caving in, the furniture she had built was damaged, and the speaker system she had installed was shot. A single bulb hung, emitting light; she and her friends had to use flashlights in the basement. They had salvaged a few thousand books, but more than 1,400 were ruined.