(CNN) — A father and his young son were identified Monday as among the three victims of a car explosion over the weekend in Pennsylvania.
Jacob Schmoyer, 26, and his 2-year-old son, Jonathan, were killed in the explosion Saturday in Allentown, Lehigh County Coroner Scott Grim told reporters. Grim identified the third victim as 66-year-old David Hallman.
The three Allentown residents died from traumatic injuries caused by the explosion, Grim said.
Schmoyer and Hallman were friends, according to Don Robinson, special agent in charge of the Bureau of Alcohol, Tobacco, Firearms and Explosives Philadelphia field office.
“We have a high degree of confidence that the perpetrator was probably killed in the incident,” Lehigh County District Attorney James Martin told CNN affiliate WFMZ earlier.
The cause of the explosion remains under investigation by authorities including the ATF and FBI.
Allentown police arrived at the scene after getting 911 calls about the explosion around 9:30 p.m., police said.
Neighbors found pieces of the burning car and human remains on the street, WFMZ reported. The explosion felt like it rocked their homes, neighbors told the station.
Robinson said the explosion was an “isolated incident.” There are no ongoing threats, according to authorities.
Robinson said authorities hope to finish processing the scene by Tuesday.
“We are making a lot of progress in both the scene and in the interview portions of this investigation,” Robinson said.
Allentown is 63 miles north of Philadelphia.