Two people died in a fiery house explosion Saturday in southern New Jersey, authorities said.

Rescuers rushed to the scene in Gloucester County’s Newfield, near Philadelphia, around 6:23 a.m. and discovered the destroyed two-story home, CBS Philly reported.

The force of the blast broke windows in homes nearby. It’s unclear what caused the explosion, but officials suspect a gas leak.

The victims were not identified, but family members told CBS they are a couple in their seventies.

No foul play is suspected and the investigation is ongoing.