Two men attempted to board the train before hers; one (aided by railroad employees) dropped a package that exploded, causing a large coin-operated scale on the platform to hit her.

A number of factors, including the bizarre facts and Cardozo's outstanding reputation, made the case prominent in the legal profession, and it remains so, taught to most if not all American law students in torts class.

[1] Under New York precedent, the usual duty of utmost care that the railroad as a common carrier owed its customers did not apply to platforms and other parts of the station.

[1] Sunday, August 24, 1924, was a warm summer day in Brooklyn, and Helen Palsgraf, a 40-year-old janitor and housekeeper, was taking her two daughters, Elizabeth and Lillian, aged 15 and 12, to Rockaway Beach.

The other, a man carrying a package, leapt aboard, with the help of a platform guard pushing him from behind as a member of the train's crew pulled him into the car.

[2][3] Contemporaneous accounts and witnesses at trial described the man as Italian in appearance, and there was speculation that the package was being taken for use at an Italian-American celebration of some sort; no great effort was made to identify the owner.

[2][3] Several days after the incident, she developed a bad stammer, and her doctor testified at trial that it was due to the trauma of the events at East New York station.

[6] Manhattan lawyers tried the Brooklyn case: Matthew W. Wood, who worked from 233 Broadway (the Woolworth Building) represented Palsgraf, while Joseph F. Keany, whose office was at Pennsylvania Station, was for the railroad, along with William McNamara.

McNamara, one of the most junior members of the LIRR's legal team, called no witnesses, and Manz suggested the entire defense strategy was to get the judge to dismiss the case.

[19] Seeger had been born in Stuttgart and came to the United States as a child; he had been elected to the Supreme Court in 1917 and was elevated to the Appellate Division by Governor Al Smith in 1926.

"[34] For example, Cardozo describes Palsgraf (whom he does not name, nor mention her daughters) as standing on the LIRR's platform, rather than waiting for a train, thus downplaying her status as a customer entitled to a high degree of care by the railroad.

"[37] Cardozo posed hypothetical situations: if a railway guard stumbles over a bundle of newspapers, and there are explosives within, will there be liability to an injured passenger at the other end of the platform?

Andrews began with a brief recitation of facts: that a railroad employee had negligently dislodged the package, the contents of which the trainman was unaware, and the subsequent explosion broke the scale and injured the plaintiff, "an intending passenger".

[46] Andrews noted the fundamental difference among the judges concerning the law of negligence: whether there must be a duty to the plaintiff, the breach of which injured her, and whether, when there is an act that is a threat to the safety of others, the doer of it should be "liable for all its proximate consequences, even where they result in injury to one who would generally be thought to be outside the radius of danger".

[47] Andrews found Cardozo's reasoning too narrow, and felt that the focus should be on the unreasonable act: driving down Broadway at high speed is negligent whether or not an accident occurs.

He listed factors that courts might consider, such as remoteness in time or space, and discussed some hypotheticals, such as a chauffeur who causes an accident, the noise of which startles a nursemaid into dropping a child, then returned to the case being decided, Mrs. Palsgraf was standing some distance away.

Frank Palsgraf, Helen's grandson, told in 1978 of "being treated like a celebrity" by a prosecutor when called for jury duty, and causing the judge to reminisce about hard nights studying the case in law school.

[58] In 1991, that association became closer, as Lisa Newell, first cousin four times removed of Judge Cardozo, married Palsgraf's great-grandson, J. Scott Garvey.

In that task, Bohlen was having difficulty dealing with the concept of duty of care in negligence, especially involving unforeseeable plaintiffs, and Prosser related that Cardozo was treated to a learned discussion by the other advisers of a case that might come before his court and, convinced by the arguments, used them to decide Palsgraf.

"[66] Manz wrote, "everyone who has sat in an American law school torts class can recall the basic facts—the crowded railroad platform, the running men, the dropped package, the explosion, and the falling scale.

"[67] Professor W. Jonathan Cardi noted, "in law school classrooms, 'Palsgraf Day' is often celebrated with food and drink, dramatic reenactments, interpretive poems, and even mock duels between Judges Cardozo and Andrews".

[72][73] Thus, according to law professor David Owen in his 2009 article, "the Restatement (Third) discards Judge Cardozo's elemental work in Palsgraf so long ago.

And ... also rejects Judge Andrew's [sic] valuable insight that juries should be offered a wide range of fairness factors, beginning with foreseeability, in figuring how far responsibility should extend".

Posner noted that in the facts of the case Cardozo "saw instantiated the basic principles of negligence law and was able to articulate them in prose of striking freshness, clarity, and vividness", in an opinion mostly written in short sentences and lacking footnotes or block quotes.

[77] University of Pennsylvania Law School Professor Kim Lane Scheppele noted that the opinion was "written by Judge Benjamin Cardozo at the height of his formidable powers".

Cowan, writing in 1938, described its holding as limited to its facts, that given the identical circumstances recurring, the railroad would breach no duty to the new plaintiff by assisting a man with such a package in boarding.

[81] Prosser in his 1953 article wondered "how can any rule as to the 'scope of the risk' evolved from two guards, a package of fireworks and a scale aid in the slightest degree in the solution of this question?

Although a clear majority of jurisdictions state that duty is the proper home for plaintiff-foreseeability, Cardozo's vision of foreseeability as a categorical determination has not been widely adopted.

Those that were shared the fate of Mrs. Palsgraf's: each case was taken on its own facts as an isolated, freak occurrence, and the broader consequence, in which death and injury became a normal byproduct of running the railroad, was disregarded.

If judges could see—if not through statistics, then perhaps through the social history of the railroad industry—just how dangerous trains were and how much death and destruction they left in their path, they may have been less inclined to think that Mrs. Palsgraf's problem was that those two men carried fireworks onto the platform that day.