The demolition of the fire-ravaged Verdi Building at 659 Union Street in North Beach has uncovered a century-old painted advertisement for Carnation Mush — vivid, legible, and newly visible for the first time since a neighboring structure was built against it decades ago.

At 659 Union Street, on the corner where North Beach's Columbus Avenue cuts through at its characteristic diagonal, the wall that faced the Verdi Building is visible for the first time in living memory. It reads: Eat Carnation Mush.

The painted advertisement — in colors strong enough to photograph — emerged this week after demolition finally came for the Verdi Building, a 1914 Italian palazzo that had spent eight years as a prominent North Beach eyesore. The building was first damaged in a 2013 fire that displaced 31 rent-controlled tenants, then gutted by a four-alarm fire on St. Patrick's Day 2018 — 140 firefighters, interior completely burned, brick shell left standing with a temporary metal shoring skeleton. Two engineering firms eventually classified the structure as an immediate collapse hazard, noting the mortar had deteriorated enough that bricks could be pulled free by hand. On June 4, 2026, the San Francisco Board of Appeals cleared the way for partial demolition.

What the teardown revealed was its own archive: a ghost sign sealed against weather and UV for however long the Verdi Building stood beside it, the paint preserved by exactly the obscurity that made it invisible.

"I'm kind of amazed how strong the colors are," said North Beach resident Evgeni Peryshkin. "I guess it was just covered and away from the sun."

Ghost signs are what the trade calls them — hand-painted commercial murals from the era when the highest-reach medium in a neighborhood was a well-positioned exterior wall. A second Carnation Mush sign survives on Market Street. Before television, before the internet, a cereal brand reached consumers through the people who painted its name in letters tall enough to read from the street.

Rose D'Amato, a San Francisco painter who has been documenting the city's surviving ghost signs in a 15-minute 8mm film, has added 659 Union to her project. She's less interested in the product being advertised than in the craft of the person who put it there.

"We're coming not necessarily to read the sign, but to look for these instances where you can learn something about the painter's experience making that old billboard," D'Amato said. "How the letters relate to the architecture, how everything's drawn."

D'Amato plans to debut the film at the San Francisco Art Book Fair opening night — July 23, 6 to 10 p.m., free admission — at 1275 Minnesota St. in Dogpatch. The fair runs July 23–26.

The sign's window may be brief. Red Bridge Partners, which acquired the Verdi Building in 2017, has proposed an eight-story building at the site: 89 apartments (15 affordable), rooftop restaurant, and 5,700 square feet of ground-floor retail. Whatever goes up at 659 Union will almost certainly cover the wall again — maybe for another century.