Nov 7, 2025 By Brad Hundt 5 min read

It was Christmas Eve 1917, and the Pittsburgh Railways trolley that bore the number 4236 was overloaded with passengers heading to work or shop or meet up with friends and family as the day wound down.

At 3:18 p.m., it roared out of the Mount Washington Tunnel, traveling much, much faster than it should have been. When it reached a curve, it went flying off the tracks and slammed onto Carson Street. The impact was said to have sounded like a bomb. It then slid down the cobblestone street, striking utility poles, a store and a fire hydrant along the way. The mishap injured 80 people and killed 23, with some of the fatalities having been dismembered.

The next day, Pittsburgh’s Gazette-Times reported, “Men and women and boys and girls, all townbound in the hope of bringing added cheer to their homes today, were crushed into a bleeding and wounded mass as the vast steel car tore along the street on its side.”

The holiday calamity ended up being the worst public transit disaster in Pittsburgh’s history. But even with its loss of life and an extended aftermath that included a prison sentence, lawsuits and bankruptcy, it’s not widely discussed or known about today. Mary Jane Kuffner Hirt set out to change that with her book, “The Mount Washington Transit Tunnel Disaster,” which was published in 2021 after almost a decade of work on it. She will be talking about it at a meeting of the South Hills Women’s Club at 7:15 p.m. Tuesday at the Lodge at Scott Township Park.

Kuffner Hirt explained on the phone from her home in Harmar Township that she started on her quest around 2009. She knew that one of her grandfather’s cousins had died in a trolley mishap in Pittsburgh, but looking through newspapers on microfilm proved to be a needle-in-a-haystack proposition – she didn’t know the name, gender or age of the distant relative, or where the accident occurred. Another complication: Pittsburgh newspapers in the early 20th century were rife with reports of pedestrians being hit by trolleys and cars and run over by horses.

But then, on Dec. 24, 2011, Kuffner Hirt’s mother saw a mention in the Pittsburgh Post-Gazette’s almanac about the 1917 Christmas Eve trolley disaster. Two days later, Kuffner Hirt set off for the Carnegie Library in Oakland. Soon enough, she found out the cousin’s name – it was Aurelia Czerny, a 45-year-old mother of seven who lived in Beltzhoover – and other details about the calamity on Carson Street all those decades ago.

She decided to keep digging.

“Before I left the library, I knew what (the name of the cousin) was, but in the next 11 years I kept finding more information,” Kuffner Hirt said.

A professor emerita of political science at Indiana University of Pennsylvania and a retired public administrator, Kuffner Hirt meticulously researched what happened before and after the accident. In “The Mount Washington Transit Tunnel Disaster,” she provides context to what Pittsburgh’s life and its economy were like in 1917, dissatisfaction with the Pittsburgh Railways Company that had been building before the accident and details on the construction of the tunnel.

“I wanted to be comfortable that I turned over all the rocks,” she explained.

The tragedy was covered comprehensively by the eight newspapers that were publishing in Pittsburgh in those pre-radio, pre-television days. That gave Kuffner Hirt plenty to work with as she assembled the book, which she finished during the COVID-19 lockdown.

“Every last one of (the newspapers) had a special edition on Christmas Eve, blaring that there had been this horrible accident,” Kuffner Hirt said. “They talked to anybody and everybody about what happened.”

Ultimately, blame was placed with the trolley’s motorman, Herman Klingler. In the verdict of a jury convened by the Allegheny County coroner, Klingler “was grossly careless in his operation of the car.” Klingler admitted on the witness stand that he had downed several drinks on that Christmas Eve, but denied being drunk when the accident happened. He ended up spending a little more than a year in prison on involuntary manslaughter charges. At least 70 civil suits were filed, with plaintiffs seeking compensation for injuries, lost wages, medical expenses and more. Ultimately, Pittsburgh Railways paid out a little more than $288,000 to victims and their families, which would be about $5 million in today’s dollars. The private company twice filed for bankruptcy in the decades that followed, and it went out of business for good in 1964.

Although public transit accidents were hardly uncommon a century ago in Pittsburgh and other cities, they were not on the gruesome scale of the disaster that unfolded in 1917. Almost 70 years later, in October 1987, another trolley car came out of the Mount Washington Transit Tunnel and again crashed onto Carson Street. Forty-one people were injured, but, unlike the 1917 disaster there were no fatalities. It was determined that brake failure caused that accident.

“We went quite a distance without an accident,” Kuffner Hirt said.

And even if it is a slice of Pittsburgh history that has largely escaped attention, people should know about the Mount Washington Transit Tunnel Disaster because it is “a part of our collective heritage,” Kuffner Hirt said.

“Knowing how it happened and who was affected allows us in a broader sense to understand what life was like in the early 1900s,” she explained.