Kuprewicz said that could take weeks, or even months, to come to a conclusion.
“The science and art of forensic analysis of such terrible tragedies are well-established,” he said. “People have been killed. Houses were terribly destroyed. It takes a while to sift through all that destruction.”

Investigators work the scene of a deadly explosion in a residential neighborhood in Pottstown, Pa., Friday, May 27, 2022. A house exploded northwest of Philadelphia, killing several people and leaving a few others injured, authorities said Friday. (AP Photo/Matt Rourke)
‘No evidence’ PECO’s natural gas caused the incident
Neighbors reported smelling gas near the homes in the days prior to the explosion, which Kuprewicz says is not unusual in these cases.
PECO representatives say the energy company’s preliminary investigation shows no evidence that the utility’s gas lines caused the explosion.
While PECO has gas mains along Hale Street, neither the house where the explosion is believed to have occured, nor its adjoining twin home that was also destroyed, were connected to those pipelines through service lines. The company says it has since carried out excavations, pressure testing of the gas mains, camera inspections of the line, and call log analysis.
“To be clear, the investigations are ongoing, and we have not been advised of any final determinations by investigating authorities,” PECO said in a statement.
Kruprewicz said natural gas is lighter than air and will dissipate above ground. But, if it accumulates in an enclosed space, like a basement or a shed, and combines with the right amount of oxygen, it can explode. Often, it only takes a small charge from a light switch or even static electricity.
In the case of a gas main, Kruprewicz said a leak can travel underground horizontally through crevices, sometimes even tunnels dug by animals like gophers. In some cases, the odorant that is added to natural gas to warn of leaks will get absorbed by the soil.
“Those are the kinds of things that the investigators have to study and investigate in further detail, so that they can rule them out,” he said. “I’m not saying this was definitely a natural gas explosion. It could have been a propane explosion, which can be even worse because it has greater explosive force.”