Plum House Explosion: Update Issued On Probe Of Blast That Killed 6

PLUM, PA — One year after a massive explosion at a Rustic Ridge residence killed six people, the cause of the blast remains a mystery. The Allegheny County Fire Marshal's office released an update on the probe Monday, the anniversary of the incident at 141 Rustic Ridge Drive.

"This investigation has been extensive and thorough and there is no time frame for when it will be complete," the fire marshal's office stated in a release. "This process is often rigorous and lengthy as investigators review evidence carefully to ensure they have as much information as possible before issuing any determination."

Killed in the Aug. 12, 2023 blast were borough manager Michael Thomas; borough community development director Heather Oravitz and her husband, Paul; Kevin Sebunia; and Casey and Keegan Clontz. The Oravitzs owned the home that exploded.

The inquiry thus far has included interviews, investigative photography/videography, drone imagery and 3D scans, debris layering, scene reconstruction, the examination of all utility connections and circuitry and other measures.

According to the fire marshal's office, an additional joint evidence exam will occur in the near future. Additional investigators, engineers, attorneys, and other experts have been added to the growing group of interested parties.

"The protocol is still under development for the testing procedures for all collected evidence," the release stated. "All involved parties need to agree on the date(s), time(s) and testing processes before the investigation can move forward."

In a report issued last month, the Pennsylvania Public Utility Commission said there was no evidence of public utility natural gas equipment causing the explosion.

"Following an extensive and exhaustive investigation into this tragedy, the Safety Division found no evidence linking public utility jurisdictional assets to the cause of the deadly house explosion and fire in the Rustic Ridge neighborhood," the report stated.

The commission will continue to assist in the ongoing local investigation, the fire marshal's office stated.