PLUM, Pa. — (WPXI) – At least one of the six victims who died in a house explosion in Plum over the weekend survived the initial blast and made a call for help in his final moments. That’s according to our news partners at Channel 11. According to sources Casey Clontz, 38, and his son Keegan, 12, along with Kevin Sebunia, 55, and Michael Thomas, 57, were all inside the basement of the Plum home that exploded. Heather Oravitz, 51, was upstairs. Her husband, Paul, 56, later died at the hospital from his injuries. The Allegheny County Fire Marshal has confirmed that the house that exploded had hot water tank issues. According to sources, the victims were in the basement working on the tank — but it’s unclear what went wrong.