The Triangle Shirtwaist Factory fire in New York City on March 25, 1911 was the deadliest industrial disaster in the history of the city, and one of the deadliest in US history. The fire caused the deaths of 146 garment workers – 123 women and 23 men who died from the fire, smoke inhalation, or falling or jumping to their deaths.

Most of the victims were recent Jewish and Italian immigrant women aged 16 to 23; of the victims whose ages are known, the oldest victim was Providenza Panno at 43, and the youngest were 14-year-olds Kate Leone and "Sara" Rosaria Maltese.

The Triangle Waist Company factory occupied the eighth, ninth, and tenth floors of the 10-story Asch Building on the northwest corner of Greene Street and Washington Place, just east of Washington Square Park. 

Because the owners had locked the doors to the stairwells and exits – a then-common practice to prevent workers from taking unauthorized breaks and to reduce theft many of the workers who could not escape from the burning building simply jumped from the high windows. The fire led to legislation requiring improved factory safety standards and helped spur the growth of the International Ladies' Garment Workers' Union (ILGWU), which fought for better working conditions for sweatshop workers.

Under the ownership of Max Blanck and Isaac Harris, the factory produced women's blouses, known as "shirtwaists." The factory normally employed about 500 workers, mostly young immigrant women, who worked nine hours a day on weekdays plus seven hours on Saturdays, earning for their 52 hours of work between $7 and $12 a week, the equivalent of $171 to $293 a week in 2016 currency, or $3.20 to $5.50 per hour.

As the workday was ending on the afternoon of Saturday, March 25, 1911, a fire flared up at approximately 4:40 PM in a scrap bin under one of the cutter's tables at the northeast corner of the eighth floor.

The first fire alarm was sent at 4:45 PM by a passerby on Washington Place who saw smoke coming from the eighth floor. Both owners of the factory were in attendance and had invited their children to the factory on that afternoon. The Fire Marshal concluded that the likely cause of the fire was the disposal of an unextinguished match or cigarette butt in the scrap bin, which held two months' worth of accumulated cuttings by the time of the fire. Beneath the table in the wooden bin were hundreds of pounds of scraps which were left over from the several thousand shirtwaists that had been cut at that table. The scraps piled up from the last time the bin was emptied, coupled with the hanging fabrics that surrounded it; the steel trim was the only thing that was not highly flammable. Although smoking was banned in the factory, cutters were known to sneak cigarettes, exhaling the smoke through their lapels to avoid detection. 

A New York Times article suggested that the fire may have been started by the engines running the sewing machines. A series of articles in Collier's noted a pattern of arson among certain sectors of the garment industry whenever their particular product fell out of fashion or had excess inventory in order to collect insurance. The Insurance Monitor, a leading industry journal, observed that shirtwaists had recently fallen out of fashion, and that insurance for manufacturers of them was "fairly saturated with moral hazard." Although Blanck and Harris were known for having had four previous suspicious fires at their companies, arson was not suspected in this case.

The Triangle Shirtwaist Aftermath & Legacy

The company's owners, Max Blanck and Isaac Harris, who survived the fire by fleeing to the building's roof when the fire began, were indicted on charges of first- and second-degree manslaughter in mid-April; the pair's trial began on December 4, 1911. 

Max Steuer, counsel for the defendants, managed to destroy the credibility of one of the survivors, Kate Alterman, by asking her to repeat her testimony a number of times, which she did without altering key phrases. Steuer argued to the jury that Alterman and possibly other witnesses had memorized their statements, and might even have been told what to say by the prosecutors. The prosecution charged that the owners knew the exit doors were locked at the time in question.

The investigation found that the locks were intended to be locked during working hours based on the findings from the fire,but the defense stressed that the prosecution failed to prove that the owners knew that. The jury acquitted the two men of first- and second-degree manslaughter, but they were found liable of wrongful death during a subsequent civil suit in 1913 in which plaintiffs were awarded compensation in the amount of $75 per deceased victim. The insurance company paid Blanck and Harris about $60,000 more than the reported losses, or about $400 per casualty. In 1913, Blanck was once again arrested for locking the door in his factory during working hours. He was fined $20.

Rose Schneiderman, a prominent socialist and union activist, gave a speech at the memorial meeting held in the Metropolitan Opera House on April 2, 1911, to an audience largely made up of the members of the Women's Trade Union League. 

The New York State Legislature then created the Factory Investigating Commission to "investigate factory conditions in this and other cities and to report remedial measures of legislation to prevent hazard or loss of life among employees through fire, unsanitary conditions, and occupational diseases." The Commission was chaired by Wagner and co-chaired by Al Smith.

They held a series of widely publicized investigations around the state, interviewing 222 witnesses and taking 3500 pages of testimony. They hired field agents to do on-site inspections of factories. They started with the issue of fire safety and moved on to broader issues of the risks of injury in the factory environment.

Their findings led to thirty-eight new laws regulating labor in New York state, and gave them a reputation as leading progressive reformers working on behalf of the working class. In the process, they changed Tammany's reputation from mere corruption to progressive endeavors to help the workers. New York City's Fire Chief John Kenlon told the investigators that his department had identified more than 200 factories where conditions made a fire like that at the Triangle Factory possible. 

The State Commissions's reports helped modernize the state's labor laws, making New York State "one of the most progressive states in terms of labor reform. "New laws mandated better building access and egress, fireproofing requirements, the availability of fire extinguishers, the installation of alarm systems and automatic sprinklers, better eating and toilet facilities for workers, and limited the number of hours that women and children could work. In the years from 1911 to 1913, sixty of the sixty-four new laws recommended by the Commission were legislated with the support of Governor William Sulzer.

As a result of the fire, the American Society of Safety Engineers was founded in New York City on October 14, 1911.

The last living survivor of the fire was Rose Freedman, née Rosenfeld, who died in Beverly Hills, California in 2001 at the age of 107. She was two days away from her 18th birthday at the time of the fire, which she survived by following the company's executives and being rescued from the roof of the building. As a result of her experience, she became a lifelong supporter of union.