PALUM (TNS) — The families of six people killed in a massive house explosion in Plum filed wrongful death lawsuits Tuesday, alleging negligence on the parts of two gas companies they say should have foreseen the deadly explosion and shedding light on some of the horrific final moments of those killed in the 2023 blast.

Those who died were homeowners Paul and Heather Oravitz, neighbors Kevin Sebunia, Michael Thomas, Casey Clontz and Clontz’s 12-year-old son, Keegan. Separate lawsuits were filed by separate law firms on behalf of each of the four families. While some personal details differ among the lawsuits, they are largely identical.

The Allegheny County Fire Marshal has yet to determine the cause of the explosion on Aug. 12, 2023, but the lawsuit filed in the Court of Common Pleas alleges that leaks within a gas line allowed methane to build up in the basement of 141 Rustic Ridge — the epicenter of the blast.

Benjamin Baer, the Philadelphia-based attorney representing the Oravitz children, said the litigation is complex and the civil proceedings will be a lengthy process.

“Even though it’s nearly two years after the event, the tragic explosion, we’re really just getting started,” he told the Post-Gazette.

The lawsuit names Penneco Gas and Oil and 17 associated companies, Peoples Natural Gas, the A.O. Smith Corp., Grasinger Homes and eight unnamed individuals listed only as John Does.

The filing blames the gas companies for creating the circumstances that attorneys say ultimately sparked the deadly blast: An over-pressurized, leaky gas line.

“We have not been served a complaint, nor have we reviewed it yet,” Penneco CEO Brian Wallace told the Post-Gazette. “However, Penneco denies any responsibility for this very unfortunate tragedy.”

A representative of Grasinger Homes declined to comment on the lawsuit. A spokesman for A.O. Smith could not immediately be reached.

A spokesman for Peoples Natural Gas said the company is aware of the lawsuit but noted the Pennsylvania Public Utility Commission found the utility company not at fault in relation to the explosion. The PUC said last year that after an “extensive and exhaustive investigation,” its safety division found no evidence linking PUC-regulated lines to the cause of the explosion.

According to the lawsuit filed Tuesday, the pressure on the 4-inch suction line had been rising since January 2023.

The average pressure measurement rose each month leading up to the explosion, from an average of 13.68 psi in January to 30.6 in May, to 48.71 in the week before the blast. The pressure on the day of the explosion reached 63 psi.

The lawsuit cites a failing compression regulator that Peoples had ordered Penneco to repair or replace a week before the explosion. Penneco, the lawsuit alleges, failed to do so, and Peoples failed to take action to reduce pressure on the line.

At the same time, there was a leak in the 4-inch suction line that attorneys say caused odorless natural gas to spill out, collect near 141 Rustic Ridge, and ultimately seep into the home’s basement through its foundation.

“On that pipe, there is a hole — a rip toward the bottom of the pipe that measures in excess of 2.5 inches,” Mr. Baer said. “This is a significant hole.”

By the day of the blast, attorneys wrote, the leaks had existed for anywhere from a few days to a few months, allowing gas to leak unchecked and, ultimately, fill the basement of 141 Rustic Ridge.

The lawsuit confirms that Paul Oravitz and his neighbors were troubleshooting his home’s hot water heater that morning and sheds light on a disaster that largely has remained shrouded in mystery.

The water heater had started making noise around 8:30 a.m., according to the lawsuit. Shortly before 10:10 a.m., one of the men who’d gathered to take a look at the appliance turned off the gas, which should have left the water heater fully disconnected from its power supply.

Unbeknown to those in the house, the lawsuit alleged, the water heater continued to run, powered by the natural gas that had filled the basement.

Attorneys blame A.O. Smith, the company that manufactured the hot water tank, for failing to warn the device could burn on an external fuel source and risk an explosion. The lawsuit also says the company should have made clear the fact that if the water heater continues to make noise once disconnected, it could mean it was still burning fuel.

At 10:22 a.m., something ignited the gas. The lawsuit doesn’t speculate on what might have caused the ignition, and Mr. Baer said that in the end, it doesn’t matter.

“It’s not a critical fact in this case. It doesn’t matter to me,” he said. “It could have been the flicking of a light switch or a foot rubbing over carpet making a static spark.

“What caused the spark,” he said, “is immaterial.”

The massive explosion leveled the Oravitz home, destroyed the houses on either side, and damaged a dozen others in the Rustic Ridge neighborhood The lawsuit accuses Grasinger Homes, the company that built and sold the houses in the development, of developing the housing tract “where it was unsafe” and “in close proximity to gas distribution lines.”

The lawsuit also sheds light on the horrific moments immediately after the explosion, noting that the elder Clontz and his son along with Thomas and Sebunia survived the initial blast — to the point that neighbors who rushed to the scene could communicate with them but were unable to reach them.

At 10:31 a.m., nine minutes after the blast, Casey Clontz called his wife from beneath the debris. In her lawsuit, attorneys for Jennifer Clontz said she felt the blast from the explosion that ultimately killed her husband and son and witnessed the explosion.

“Casey told his wife that he and their son Keegan were not going to be able to escape, they were going to die, and he loved her,” attorneys wrote.

The lawsuit continued: “Jennifer heard her son Keegan crying and screaming during the call … Jennifer pleaded with Casey to find a way out, told him to try to control his breathing, and that she loved him.”

Among the houses destroyed by the blast was 139 Rustic Ridge, home of Michael Thomas and his wife, Jacqueline. Their home was demolished, Ms. Thomas’ attorneys wrote in her lawsuit, and she fell from the second floor to the first when the structure collapsed. She suffered second-degree burns, scarring, and needed multiple stiches, attorneys wrote.

Those trapped in the basement, the lawsuits said, “suffered horrific pain and suffering and unimaginable fear of impending death as they survived the explosion but were unable to escape the basement of the Oravitz home.”

The father, son, and two neighbors were ultimately recovered from what would have been the home’s basement.

The Oravitzes, too, survived the initial blast, suffering “horrific pain and suffering and unimaginable fear of impending death due to burns and explosion-related injuries …”

Heather Oravitz was found outside the garage area of the home. She died a few hours later. Paul Oravitz was found in the rear of the home and died four days later, having suffered burns to more than 70% of his body, according to the lawsuit.