A series of blasts at a plant making WWI explosives killed about 200 people a century ago, writes LEN BARCOUSKY

Wrapped inside the white handkerchief were a belt buckle, a pocketknife and the clasp from a change purse. Those few items had been crucial in identifying the remains of Ralph Keenan’s grandfather. James Keenan had been among an estimated 200 people who died 100 years ago May 18 following explosions at a chemical plant outside of Oakdale. The bodies of many of the victims were obliterated in the blasts. A minority could be identified by the things they had been carrying or wore.

Dan Prevade, 46, grew up in Oakdale less than a mile from the site of the disaster. A veteran social studies teacher at West Allegheny High School, Mr. Prevade has studied, lectured on and written about his hometown tragedy.

The memory of his 2012 meeting with Ralph Keenan has remained strong. “The most fascinating moment of all my research was when he opened up that handkerchief,” Mr. Prevade said..

The Aetna Chemical Co. plant covered 15 acres in North Fayette. The site, about a half-mile east of Oakdale, was bounded by the North Branch of Robinson Run and the Pennsylvania Railroad’s Panhandle line. The railroad tracks have been pulled up, and the right of way now is part of the Panhandle hiking and biking trail.

Little remains of the plant, which was not rebuilt after the blasts. Since last year, however, the tragic events of that spring day in 1918 have been commemorated on a trail-side plaque erected where the bike path intersects Union Avenue in Oakdale. Mr. Prevade and Ernie Thomas, 67, a retired geologist with a similar interest in local history, led the effort to raise $1,500 for the marker.

Most of the money was raised in small donations, Mr. Thomas said. They were augmented by larger gifts from Industrial Scientific Corp. and the West Allegheny Foundation.

* On one recent sunny spring afternoon, the most common sounds heard along the bike trail near the plant site were birdsongs.

The scene was much different a century ago.

In its story the day after the tragedy, The Pittsburgh Gazette Times reported that nine explosions occurred in the interval just before noon and 4 p.m. “Many families living in or near Oakdale were rendered homeless when their dwellings were wrecked or burned,” the newspaper said. “Fires in many sections of the works and nearby buildings hampered rescuers. Injured men in the path of the flames, unable to help themselves and out of reach of those who would have rendered assistance, were burned to death.”

Despite the continuing danger, volunteer rescuers and medical professionals rushed to the scene. “All available doctors, nurses and ambulances from Pittsburgh, Oakdale, Carnegie and other boroughs ... were sent to the plant after the first blast,” The Gazette Times story said.

Mr. Prevade found multiple newspaper stories about heroic actions that day. Several described how James Keenan, 66, rushed into the plant after the initial explosion. He and other rescuers were among those killed or wounded in subsequent blasts.

Chance played a major role in who lived and who died in the conflagration.

John B. Johnston was plant superintendent. The first blast collapsed the headquarters building, trapping him and his secretary, Homer L. Andrews, in the ruins.

In a Gazette Times story that ran May 20, Johnston told a reporter that he had reached for Andrews’ hand but could not move his colleague. When he tried to climb out of the rubble toward an opening above him, he only succeeded in moving about 10 feet before getting stuck again. “The mass of wood by this time started burning, and the fire began eating its way toward me,” he said. “Just when I thought I would faint from the heat and smoke, a second explosion shook the debris from me and hurled an iron bar into the wall about 2 feet above my head.

“It stuck fast, and by grasping it with both hands, I was able to pull myself to the top of the wreckage and got my lungs full of fresh air,” he said.

He was rescued from the ruins of the office and transported to Allegheny General Hospital with severe burns. The body of his secretary was found later in the rubble.

“Among the many acts of heroism performed at the disaster in Oakdale [on] Saturday, that of Miss Marlyn Ashelman … stands out as the most conspicuous,” the Gazette Times reported. Ashelman, a 22-year-old nurse working at a North Side hospital, lost her leg in what was the final blast at the plant. She had been dressing the wounds of an injured worker when she herself was hurt.

She had been the first to respond when Dr. Lee F. Milford asked for volunteers from among the staff at St. John’s Hospital in Brighton Heights.

“When the ambulance reached the plant, I ordered Miss Ashelman to remain with it on a hill while I went to see what I could do,” Milford told the newspaper. “While I was dressing the wounds of some of the victims, Miss Ashelman left the ambulance, not being able to restrain the impulse to relieve the suffering of the bleeding men all around her.”

The physician also saw a man operating a motion-picture camera nearby, standing atop a metal tank and taking pictures of the destruction.

“While I was attending one of the victims, a terrific blast shook the earth, and I was hurled about 50 feet into a gully,” he told the newspaper. The doctor was bruised and battered but otherwise not injured.

Those around him had been less fortunate. The camera operator and the metal tank on which he had been standing had disappeared. His nurse had been badly hurt.

“I found Miss Ashelman bleeding on the ground and saw that her right leg had been severed,” Milford told the paper. “I had exhausted my supply of bandages and had to use my raincoat as a tourniquet to stop the bleeding. She never made a whimper, although she knew the extent of her injury.” Her bigger worry, she told Milford, was how news of her injury would affect her father.

Ashelman’s story struck a chord with readers after her injury had been mentioned in a May 19 report on the disaster.

By mid-afternoon the day after the explosion, “16 boxes of cut flowers had been received by the injured nurse” at St. John’s Hospital, where she was being treated, the newspaper said. “Nearly all the flowers were without any sender’s name attached.” Dozens of other people made phone calls or stopped by the hospital. “Upon being informed that she probably would live, [they] expressed wishes for a speedy recovery.”

Ashelman did survive. She returned to her nursing career, retiring as assistant superintendent of nursing at Union Hospital in Dover, Ohio. She died in 1971.

On the day of the blasts, Pittsburgh had been the site of a Red Cross parade that drew 40,000 marchers, mostly women, from all over the county. There would have been several hundred more, the newspaper said, but some of the Red Cross volunteers headed straight to Oakdale when they learned about the blasts. The women, “with their white veils and dresses, could be easily distinguished” as they walked or rode to the disaster scene, the Gazette Times reported.

With an estimated 200 people killed by the explosions and the fires that followed, the Aetna Chemical death toll was more than double the number of fatalities resulting from the better-known Allegheny Arsenal explosion in Lawrenceville in 1862. * Aetna Chemical was a major manufacturer of explosives, and the main product at its Oakdale plant was TNT.

Oakdale residents had complained about the danger that the Aetna plant posed to nearby neighborhoods when the plant began producing material for the French army during World War I. An explosion at the plant on Sept. 15, 1916, had killed five workers.

The U.S. entrance into the war in April 1917, however, increased the demand for Aetna’s products, and talk about relocating the plant ceased, Mr. Prevade said.

The multiple explosions and massive loss of life immediately raised questions about sabotage.

While fires still burned at the ruined plant, Aetna began what the Gazette Times called “an informal probe into the source of the explosions.”

The company had been using a chemical called Dynol as part of its manufacturing process. The company investigation pinpointed the most likely cause of the first blast as “an overheated pan in the Dynol department,” the Gazette Times reported on May 20.

The company and the U.S. War Department disagreed, however, on why the pan exploded. Army Capt. J. Herbert Hunter testified that Aetna’s TNT manufacturing process made use of sodium bicarbonate, commonly known as baking soda. The War Department’s Ordnance Division had “cautioned against” use of that chemical because it made the TNT mixture unstable, the Gazette Times reported on May 21. H.L. Wollenberg, Aetna Chemical’s general manager, protested. The company had used sodium bicarbonate as a neutralizing agent, but the manager claimed his firm had not been definitively informed that the practice was dangerous.

In addition to the historical marker, victims of the disaster are remembered on a nearby hillside above the borough. Many of the casualties from the explosion are buried in the Oakdale Cemetery, a half-mile south of town. While some, like James Keenan, are in family plots, many others are buried in a mass grave. Atop that burial site is a tall granite monument erected by Aetna Chemical.

Inscribed on the memorial are the names of 39 of the employees who died in the blasts. “Like soldiers,” an inscription says, “they died in their country’s service.”