PLUM, Pa. (WPXI) — Allegheny County authorities have released an update on where the investigation into a house explosion in Plum Borough last Saturday stands. The Allegheny County Fire Marshal remains the lead investigator on the case and is working to determine the origin and cause of the explosion on Rustic Ridge that killed six people, destroyed three homes and damaged at least a dozen more. ACFM now says 38 fire agencies from Allegheny and Westmoreland counties responded to the scene on the day of the explosion. In addition, three police departments and eight EMS agencies from the same counties responded. ACFM says the six victims were all found on the same property. One victim was found in the garage, and four others in the basement. Paul Oravitz was rescued from the rear yard and transported to the hospital, where he later died. Three houses will be torn down once released by ACFM. Another 10 are currently uninhabitable but aren’t necessarily going to be torn down. Plum Borough says property owners will have to work with a structural engineer to determine next steps. ACFM says it’s using a systemic approach in its investigation and is currently “identifying heat sources, first fuel ignited, and the act/circumstances that brought them all together.” Additionally, ACFM says Peoples Gas has worked with deputies daily and included them in system testing.