Wrote Susan Dominus in an August 16, 2010 New York Times story, “… what no one seems to know, is who went to the effort of painting the stroller that uncomfortably chalky Mylanta white — taking a paint brush to the cup holder, the bag zipped in back, the mesh basket below, even the chain and padlock attaching it to the parking sign.”

More: ” ‘Every day my kids say, ‘What does that mean? Did a baby die?’ ” said Lauren Abrams, a midwife who lives on Union Street…. ” ‘Usually I cop out and say I don’t know what it is.'”

Up top, the ghost stroller in situ on the corner of Sixth Avenue and Union Street in Park Slope, Brooklyn.

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If you sit on the front stoop of your building practically every day for 25 years, the way James Rudnick has, people expect you to know what is happening on the block. So every day, people stop and ask Mr. Rudnick — Jimmy from Union Street, as he’s known here in Park Slope — what he knows about the white-painted stroller that has been padlocked to a parking sign on the corner of Union Street and Sixth Avenue since the beginning of the month.

Sometimes the passers-by look curious; sometimes they are distraught, concerned by the three plastic roses — peach, pink and red — tucked behind the straps, which give the stroller the distinct look of a memorial commemorating some grim accident.

Mr. Rudnick does not, in fact, know the origins of the stroller, although he knows one thing: if a child had been killed in traffic on a corner anywhere nearby, he would know. “Or someone we know would know,” added his wife, Sara Bernstein, who sat beside him on the stoop on Monday. “But we would know!”

What they do not know, what no one seems to know, is who went to the effort of painting the stroller that uncomfortably chalky Mylanta white — taking a paint brush to the cup holder, the bag zipped in back, the mesh basket below, even the chain and padlock attaching it to the parking sign.

People at the New York City Street Memorial Project, which installs most of the “ghost bikes” — white-painted bikes throughout the city that commemorate sites where cyclists have been killed — said they had no idea who had installed the stroller. And a police spokesman could find no record of a fatal car accident this summer in the area.

The ghost stroller, as it has been named by several Brooklyn blogs, is the visual equivalent of that famously succinct bit of fiction, supposedly written by Ernest Hemingway: “For sale: baby shoes, never worn.” But where that story is all restraint, the ghost stroller, in its bulk, feels more like an assault, possibly a deliberate upending of the Park Slope dream of better parenting through good taste. Right across the street from the stylish maternity shop Boing Boing, with its earthenware tea sets and retro-patterned baby slings, and a block from the bar Union Hall, which earned fame for banning strollers, the installation is experienced, easily, as a comment on the neighborhood’s ever-encroaching culture of cute.

A clerk at the Tea Lounge on Union Street said that when the stroller first appeared, everyone coming in seemed saddened by it, but that when no news materialized, the talk turned more to the possibility that it was “some sort of warning — like a ‘God forbid this happen here.’ ” A second clerk, a young man with tattoos crawling up his arm, expressed great concern about the way mothers in the neighborhood “push their strollers out into the street before they can see if a car is coming.” (Indeed, a Department of Transportation report released Monday found there were more pedestrian traffic fatalities and serious injuries in Brooklyn than in any other borough.)

“Whoever did it probably is up there,” said Ms. Bernstein, back at the stoop, waving her hand up at the buildings on the corners of the street. “Watching.”

What would that hypothetical artist see? People talking to their neighbors on the stoop about the nature of art, about the nature of death — the kinds of conversations that artworks, beautiful or not, hope to provoke.

“Every day my kids say, ‘What does that mean? Did a baby die?’ ” said Lauren Abrams, a midwife who lives on Union Street and was chatting with Mr. Rudnick and Ms. Bernstein. “Usually I cop out and say I don’t know what it is.”

“We don’t know what it is!” Mr. Rudnick reminded her.

One ponytailed mother pushing a Bugaboo walked by the stroller without breaking pace, but her eyes lingered on it a moment longer than necessary. She flicked her gaze back to her own baby’s face for a moment, then stared straight ahead, safe to return to her own thoughts, or the nonthoughts of exhausted new mothers everywhere.

A tall woman wearing her baby in a sling craned her head to keep looking as she walked by at high speed. She gasped: “So tragic!”

Many other mothers, possibly used to the sight by now, pushed their own full strollers by the empty, etiolated version without so much as a sideways glance.

Symbols are one thing; the demands of new lives are supremely insistent.

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Dominus updated the story in a New York Times “City Room” blog post on August 17, 2010, writing, “Maybe the sight of a reporter nosing around with a notepad for Tuesday’s Big City column made the mysterious creator of Park Slope’s ghost stroller — a stroller painted white to look like a memorial — think the object had received more than enough attention.

“Or maybe a Park Slope parent got fed up with the gruesome image and sawed the padlock, then dumped the stroller in a pile of garbage in front of someone’s home on Sixth Avenue near Berkeley Place, where it was seen lying around 9 p.m. on Monday.

“But the Ghost Stroller lives to tell another tale, one of warning: A crossing guard who works on the corner of Berkeley and Sixth, in front of Public School 282, said Tuesday morning that she was appalled that someone had moved what she assumed to be a memorial for a young child. She placed it in front of the school as a warning to cars and pedestrians about road safety.

“Let us know if you see the Ghost Stroller turn up somewhere else.”