When a nurse living on the Upper West Side checked an app for neighborhood bulletins last fall, she learned about the recent discovery of a Jacob Lawrence painting in an apartment a few blocks away. It had turned out to be one of five panels long missing from the artist’s groundbreaking 30-panel series “Struggle: From the History of the American People,” which was on view at the Metropolitan Museum of Art, right across Central Park.

The name Jacob Lawrence rang a bell.

She walked over to look more closely at a small figurative painting on her dining room wall, where it had hung for two decades, its signature barely legible. It was a gift from her mother-in-law, who had taped a 1996 New York Times profile on Lawrence to the back. The nurse, who had only glanced at the back while dusting, learned from the app that Lawrence was a leading modernist painter of the 20th century — and one of the few Black artists of his time to gain broad recognition in the art world.

Could lightning strike twice in just two weeks’ time? The woman told the story to her 20-year-old son, who had studied art in college and quickly Googled the Met’s exhibition. He found a murky black-and-white photograph of their very painting being used as a place holder for Panel 28. It was titled “Immigrants admitted from all countries: 1820 to 1840—115,773,” and the wall label read: “location unknown.”

“It didn’t look like anything special, honestly,” said the owner, who is in her late 40s and arrived in New York from Ukraine at 18. “The colors were pretty. It was a little bit worn. I passed by it on my way to the kitchen a thousand times a day,” she said in a phone interview.

“I didn’t know I had a masterpiece,” she added.